Top 10 Dynasty First Basemen - Fantasy Baseball Prospects

Sean Scampton previews the top 10 first base prospects in dynasty league baseball to start the 2019 offseason. These 1B-eligible hitters should be on the radars of every dynasty baseball player.

It might seem like I drew the short straw among the prospect analysts here at RotoBaller, but I actually picked this assignment! You won’t see many of these names on top 100 lists. Despite being one of the positions from which teams expect to get the most offensive production, first base gets the least amount of respect on prospect lists. So “exciting” first base prospects are few and far between, but that doesn’t matter for us. We’re all about the fantasy goodness here at RotoBaller, and there's a lot of opportunities to find surplus value at the position.

So, let’s look at the top 10 fantasy first base prospects for what they are: gaudy counting stat monsters. Ok, maybe that’s a little over the line, but the common element you’ll notice with most of the guys highlighted here is power. Pop reigns supreme with players who are only expected to man first, but we do want to make sure that our guys can actually play the position and don’t get shuffled to DH or, worse yet, never get a shot because of the glove. So, with all that said, rest assured that the guys highlighted here can actually play first base, as well as have the potential with the bat to put up all those curvy counting stats.

Here are RotoBaller's top 10 dynasty first base prospects for 2019, plus a couple of extras because I love you. Make sure that you keep it here at RotoBaller for all of our real-time breakdowns of trades, signings, and cuts as they happen. Go into your draft season knowing what’s up. After all, if you can’t win, why try? Let’s get those chips.

• Fantasy baseball trade analyzer
• BvP matchups data (Batter vs. Pitcher)
• PvB matchups data (Pitcher vs. Batter)
• Who should I start? Fantasy baseball comparisons
• Daily MLB starting lineups
• Fantasy baseball closer depth charts
• Fantasy Baseball live scoreboard
• Fantasy baseball injury reports

Peter Alonso (1B, NYM)

ETA: 2019

Perhaps the single most complete bat regardless of position in the minor leagues, Peter Alonso was ready in August of 2018. The New York Mets didn’t promote him for… reasons. But the 24-year-old is ready to take the everyday position for the big-league club, and really most big-league clubs, immediately. He’s no. 1 with a bullet because of all of the players listed, Alonso is the one that is pretty much guaranteed to be an MLB regular.

When it comes to hitting, Alonso does almost everything well. His 2018 campaign across two levels featured 36 home runs, 119 runs batted in, a .975 OPS, a 13.2% walk rate, a .284 average, and an almost disturbing .298 ISO. One could say he pulls the ball too much (although he does) and that he struggled with too much swing-and-miss in Triple-A, but in reality, these are just nitpicks.

He’s athletic enough to handle the position on a regular basis, so there’s no fear of losing positional eligibility. He’ll be a top 200 pick in redraft leagues this season once the world gets a look at him in spring training, and he might actually be worth it. If you can get him in dynasty leagues, don’t hesitate.

Nathaniel Lowe (1B, TB)

ETA: 2019

Outside of Alonso, I think I’m more excited about Lowe than any other player on this list. Once not thought to have the pop necessary to hit enough for the position, Lowe came into 2018 with a mission and some new man-strength. The former 13^th round pick jumped from High-A to Triple-A in a single year, slashing a robust .330/.416/.568 with 27 home runs, 102 runs batted in, a 12.4% walk rate, and a modest 18.7% strikeout rate. To call Lowe a “diamond in the rough” might be disrespectful to just how bright he can shine.

Few prospect heads are going to rank Lowe this high, citing lack of pedigree and high BABIPs across his career. But that opinion disrespects the adjustments that Lowe has made to his approach, the specific skills he’s always brought to the table, and the physical maturation he’s experienced. The hit tool was always expected to be plus, but coaching led to him to tap into the raw power that his younger brother Josh, a Rays first-round selection in 2016, was able to access earlier in life, thus leading some to believe that Nathaniel just didn’t have it in him.

Now standing 6’4” and weighing in at 235, the 23-year-old brings an imposing presence to match his production. He uses the whole field well as a hitter as opposed to being pull dependent, controls the plate well, and makes all the routine plays. The only reason he’s not a top 50 prospect is that he didn’t have the “pedigree” coming out of the draft. But make no mistake, he’s the most exciting first base prospect other than Alonso in baseball.

Matt Thaiss (1B, LAA)

ETA: 2019

Los Angeles Angels’ first base prospect Matt Thaiss wins the 2019 Brandon Belt Award for the best hitter that no one thinks can hit for power. The scary part is they may be right. Since the Angels made him the 16^th overall pick in 2016, Thaiss has made 1,479 plate appearances and hit a grand total of just 31 dingers in that time frame. Needless to say, that’s the worst home run percentage of any player we’ll be highlighting in this article.

So why is Thaiss listed above monster power hitters like Bobby Bradley? It’s because the former University of Virginia standout has what might be the most advanced approach at the position. He combines elite contact skills with incredible plate awareness. Over 400 plate appearances at Triple-A in 2018, Thaiss produced a reasonable .277/.328/.457 and struck out just 17% of the time. But what was impressive was the way that he spread the ball to all fields, produced more lift to his contact than in previous seasons, and raised his ISO significantly from 2017.

Thaiss is adjusting his approach to become more successful and it’s already yielded more pop than was expected in 2018. Plus, he did so while displaying an ability to see tons of pitches and pick his spots against advanced competition. If you had me guess which player on this list has spent the most time studying how Joey Votto approaches hitting and seeing pitches, I’d say Thaiss without hesitation.

Brent Rooker (1B, MIN)

ETA: 2020

With the Twins’ Brent Rooker, we return to the classic, platonic ideal of a first baseman with massive pop. The 24-year-old from Mississippi State is a straight man and, once he made an adjustment in college, began to use his lower half and unlocked the natural power in his swing. In 2018, Rooker nailed 22 dingers in Double-A and probably could’ve had more had he been more selective at the plate.

But of course, with great power comes great swing-and-miss. Rooker follows in the long and proud line of big hitters who have big strikeout numbers. Despite the “three true outcomes” statistical profile, Rooker brings a more methodical approach than his production would suggest. He’s shown a willingness to make adjustments to his approach, and the eye is good enough to draw plenty of walks. Even if the hit tool doesn’t improve greatly, the pop will play enough to get on the field.

Rooker has the potential to be one of the next great power bats in the bigs, or the set a new strikeout record if he gets the playing time. He has the most prodigious pop in the Twins’ system, meaning he’s very likely to at least get a shot at the major league roster. This is the organization that gave 783 at-bats to Kennys Vargas, after all. Rooker doesn’t have the superstar upside of Alonso or Lowe, but he’s the best bet to hit 30 home runs in the bigs on this list.

Pavin Smith (1B, ARI)

ETA: 2020

The seventh overall pick in 2017, Pavin Smith began his pro career as a highly regarded, very advanced bat that would move quickly through Arizona’s minor league system. Sure enough, he rewarded that trust in 2017 with a .318/.401/.415 line with more walks than strikeouts in his first 223 professional plate appearances.

The only element missing was the pop, but that concern was quickly written off. Moving to High-A in 2018, it could be argued that Smith disappointed with a .255/.343/.392 line and 11 homers. The great walk-to-strikeout ratio stuck around, but the power that has been expected since he was drafted has yet to materialize. A .137 ISO is far less than was hoped for from a player who finished his junior season with more home runs than strikeouts.

All that said, the Diamondbacks clearly believe in Smith, as they were willing to part with veteran superstar Paul Goldschmidt, freeing the position up for the foreseeable future. While the power hasn’t yet shown up, everything else that made him a very reasonable seventh pick despite a lack of athleticism has translated. The raw strength is still there, so there’s no reason to think that at just 22-years-old the power won’t come. We’ve seen plenty of guys take a couple of seasons to get their pop going, and Smith’s approach is good enough that he’ll have a big-league future even if he never hits the lofty heights once dreamed for him. He’s behind Rooker because of the power, but you could flip them and I’d be fine with it.

Evan White (1B, SEA)

ETA: 2019

I have to be honest, I went back and forth on White more than anyone. He went from fourth to off the list entirely to finally settling at sixth because the editors were waiting and I just had to write the damn thing. White is one of those guys that pops more when you watch him than he does in the box score. He brings little power to the table, but is such a good hitter that it might make up for it. I feel the same way about him as I feel about Jesse Winker, a potential OBP stud who fits better as a weird lead-off hitter than he does in the middle of the order.

The 22-year-old has shown the kind of annual improvement I love to see from prospects, and I’m clearly a sucker for a guy who can control the plate. He’s also among the better athletes at the position and would be a candidate to move to a corner outfield spot if the Mariners weren’t deadest on keeping him at first, which they are. In dynasty, I’m grabbing him at current value and hoping that a late bloomer power surge brings another level of value. There’s really no way to expect something like that, but the floor is high enough for White that I’m confident he’ll carve out a significant major league role, even if the ceiling is much lower than the guys ranked above him.

Nick Pratto (1B, KC)

ETA: 2021

I struggled mightily on where to put the Kansas City slugger. I knew he was top 10, but there are enough questions surrounding his ability, role, and the organization that I’d rather have Smith and White on my dynasty roster. All that said, Pratto might be the most talented of the three, bringing an advanced bat for his age to the Royals with the 14^th pick in the 2017 draft. He struggled mightily in his first pro season but recovered in 2018 to slash .280/.343/.443 with 14 home runs and 22 stolen bases in A-ball as a 19-year-old.

There’s the chance for Pratto to rock a plus hit tool with plus power and the athleticism to steal some bases, which sounds an awful lot like Paul Goldschmidt. But that future would require a lot to go really right, and it would have to happen with an organization that doesn’t have the best recent reputation with developing bats (see Starling, Bubba and Colon, Christian).

In terms of upside, Pratto has as much ceiling, if not more, than Peter Alonso. But just as there’s a lot of time for the now 20-year-old to develop, there’s a lot of time for something to go wrong. Unfortunately for prospects, the latter tends to happen far more often than the former, and Pratto doesn’t have the loud pop tool to propel him further if the hit tool doesn’t develop as expected. Pratto will debut on a lot of top 100 lists this offseason, but this might also be the peak of his value.

Seth Beer (1B, HOU)

ETA: 2021

The Astros made the former Clemson Tiger the 28^th pick overall in this past year’s draft, and he probably has more question marks than any player drafted in the first round. Beer was extremely productive in college, but struggled in showcases. He’s walked twice as much as he’s struck out but had never before used a wood bat at any point in his career.

You just don’t know how a guy is going to handle a pro bat until they start to use them. While the power and bat speed always looked great in college, would he have the strength and touch to translate that to wood? The Astros took a leap of faith, but it’ll be at least another season before we know how it’ll shake out.

Houston has been aggressive with the 22-year-old, moving him three levels in his first professional season and topping out at High-A. Thus far, he’s risen to the challenge, slashing a combined .304/.389/.496 with 12 homers and just an 18.8% strikeout rate on 260 at-bats. He’ll likely start 2019 in Double-A, at which point we’ll get a better idea of how the bat and approach hold up to far better pitching. Personally, I’m cautiously optimistic, and I’ve typically found him ranked below guys like Bobby Bradley and others that I’m down on like Rowdy Tellez, Josh Ockimey, and Grant Lavigne. Beer really could’ve been ranked for me as high as sixth, and readers should know that there’s almost no ranking distinction between these three.

Tyler Nevin (1B, COL)

ETA: 2021

Another personal favorite that is ranked higher for me than perhaps for many other prospect heads, Tyler Nevin has slowly begun to tap into the potential that made him the 38^th pick overall in 2015. You see that sometimes with bats that require more finesse can develop less quickly, and Nevin isn’t the kind of tool shed like some of the earlier players on this list. Rather, he’s developed as a true hitter, growing bit by bit, year over year, in areas that you always hope players will grow in but sometimes never do.

Everything, from the approach at the plate, to pitch recognition, to knowing when to muscle up on swing and when to lay off has shown improvement since his draft year. That growth came to a head in 2018, where the 21-year-old slashed .328/.386/.503 with 13 homers and just an 18.5% strikeout rate over 378 at-bats. That sort of all-around, few weaknesses game defines Nevin as a hitter.

Nevin is the kind of consistent improver that could just kind of stick around as they slowly figure it out. He’s not the same kind of player, but I think of Mitch Moreland as a guy who had just enough success to stay in the bigs and improved in little ways every season until he became a more integral and valuable player. Nevin has a higher ceiling than Moreland ever did, but the point that he’s a methodical and slowly evolving hitter holds firm. I personally love guys who seem boring but don’t hurt you anywhere, and I’m excited that Nevin could become that kind of first baseman.

Triston Casas (1B, BOS)

ETA: 2023

While Brent Rooker is the best bet to hit 30 home runs in the bigs, Boston’s prep first-rounder Triston Casas has among the best power potential in the game. The 18-year-old stands 6’4” and 238 already, is a better athlete than his size might suggest, and some scouts have graded his raw power at the top of the grading scale. That 80 grade puts him in the same class as Joey Gallo, Eloy Jiminez, and one-time top prospect Brandon Wood.

That last one I mention specifically because it’s helpful to remember how even the best tools can fail due to lack of development. Casas has a long way to go before he sniffs Fenway, and that’s why teenage prospects bust more often than not. You get excited by the potential, the raw talent awaiting the chance to be unlocked, but you never know how things are going to go once a kid gets a taste of players that are as good as he is.

There’s a lot of conjecture to Casas mostly because he’s taken all five plate appearances in his pro career, striking out twice and walking once with no hits. But the tools are loud enough that it makes sense to dream, and Casas brings a potent combination of pop, a controlled swing, and good athleticism at the position. He even has a 94-mph fastball, so a Brendan McKay-lite two-way future isn’t out of question. Triston Casas is an exciting prospect, and one I’ll be trying to acquire in dynasty leagues, but don’t buy in too hard and too fast.

The Two-Way Elephant in the Room

Brendan McKay (SP, OF, 1B(?) TB)

ETA: 2020

Since I’d probably be lynched if I didn’t at least discuss him, let’s address the absence of Brendan McKay. The reason that the best two-way prospect since Dave Winfield isn’t listed as one of the best first base prospects in baseball is that, well, I don’t think he’s going to ever be a first baseman. I mentioned in the opening that the likelihood of sticking at the position is a qualification of making the list, as it doesn’t matter what people think you are if you don’t have the positional eligibility in fantasy (I’m looking at you, Willie Calhoun). Put simply, if he doesn’t play first base in the majors, then he doesn’t make the cut.

As a hitter, McKay is indeed an impressive specimen. He brings a very advanced approach, a gorgeous lefty swing, and plenty of raw power to access as he learns to get to it in games. He struck out too much at high-A and slashed just .210/.317/.403 in 139 plate appearances, but he has all of the tools to produce big home run numbers and a solid .270+ average. McKay also to be a dynamic starting pitcher who struck out 103 batters in 78.1 innings and hurls four potentially plus pitches with above-average command. He’s a potential ace who can hit, but not necessarily a hitter who can pitch. It’s a nuanced distinction but remembering that the Rays view him as a pitcher first is critical to our expectations of him.

I frankly don’t care if he plays first in the minors. I’ve been watching the Rays closely since Esteban Yan was supposed to be the next big thing, and I can tell you that there’s a very low likelihood that McKay settles in as some simple split between a starting pitcher and a first baseman on off-days. Anyone who drafted or watched Shohei Ohtani this season knows that the two-way expectation is fraught with risk, and he wasn’t even expected to play the field. The Rays are too smart and too focused on positional flexibility to depend on McKay as an everyday or even part-time fielder. If he’s able to develop as a starter, which has been the Ray’s focus so far in McKay’s young career, he’ll more likely DH on off-days while one of the team’s other swiss army knives takes first. The ascension of Nathaniel Lowe has potentially eliminated the need for a long-term solution at first for which McKay was once envisioned, and since it’s the Rays I wouldn’t be surprised if they only shifted him to first to bring in a reliever while keeping McKay in the lineup and allowing him to rotate back to the mound, which they did in limited capacity last season.

TLDR; McKay won’t play first base enough to be a long-term option at that position, but he’s still an incredible dynasty asset that you should own anyway.

Extra Innings

Bobby Bradley (1B, CLE) ETA: 2019

I don’t think he hits enough to carve out an everyday role, but Bradley’s another guy with monster power. His approach and swing haven’t shown much improvement, but I wouldn’t be surprised if he had a season or two ala Mark Reynolds where he runs into enough homers to become fantasy relevant.

Ibandel Isabel (1B, CIN) ETA: 2021

A tool shed but a terrible hitter, Isabel’s best case scenario is as a platoon bat or pinch hitter in situations where you don’t mind a strikeout. He hit 36 homers in 2018 after being acquired from the Dodgers, but he also struck out in 40.5% of his at-bats that season. Keep your eye on the 23-year-old Dominican, as even a minor improvement to his approach or contact rate could vault him to a consistent role, but it’s a real longshot.

Luken Baker (1B, STL) ETA: 2021

Because you can’t have a top prospect list with a Cardinal, I present Luken Baker. The 75^th overall pick in 2018 is another big power, questionable hit prospect. Of the ones on the outside of the top 10, however, Baker has the best shot of making this list next season. He’s not a great athlete, but he has a good enough approach at the plate that I feel fine saying that the Cardinals’ organization can help him get to his 70-grade raw power in games more often. I’ll be keeping my eye out for him in 2019.

Grant Lavigne (1B, COL) ETA: 2022

If my research has told me anything, it’s that I’m far lower on Lavigne than most. The 42^nd overall pick in 2018 is a talented hitter who does the things that I typically gravitate towards. But when I’ve watched him I’ve seen the kind of swing and approach that may fall apart against better pitching. He hit an impressive .350/.477/.519 with six homers and 12 steals in rookie league last season, but that was a very hitter-friendly environment that has created false positivity before. I’m not saying I’m out, but I want to see more before I even consider moving him above any of the other guys on this list.

More MLB Prospects Analysis