Hitter Fantasy Baseball Breakouts - Risers to Watch and Waiver Wire Outlooks (Week 20)

August 9, 2025

Jarod's hitter fantasy baseball breakouts, sleepers, and risers to watch for Week 20 of 2025. His list includes waiver wire outlooks and underachieving hitters so far.

Welcome back to the Fantasy Baseball Breakout Hitters article for Week 20 of the 2025 MLB season. The focus of this article is to highlight players who could be on the verge of a breakout, citing current active hitting streaks along with recent leaders in batting average, stolen bases, and isolated power (ISO).

This week, we'll check in on some hot names like Andrew Vaughn, Daulton Varsho, and Agustin Ramirez. We'll also take a look at a guy who is hitting well now, but whose bat could go cold soon.

Who should fantasy managers look to grab off the waiver wire or even plug into their DFS lineup this week? Let's check it out below!

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Hit Streak Leaders

Data through 8/6

Now this is a motley crew. No Bobby Witt Jr., Zach McKinstry, or J.P. Crawford on this list like we've seen multiple times this season. However, the name at the top, as surprising as it might be based on how his season was trending before, has been hot since he joined the Brewers.

Andrew Vaughn (12 games)

It feels like this is the last chance you'll get to roster Vaughn. I know his track record won't make you feel warm and fuzzy about it, but I mentioned him in a preseason breakouts article, then early in the year, he was featured as an underachiever in this article as a player who was expected to rebound.

It wasn't looking good after he was demoted to Triple-A by the White Sox, but then, five games into his Brewers career, I featured him again in my "Second Half Breakouts" article. Now here he is, the player with the longest hit streak in the majors.

Not only does he have a 12-game hit streak going, but he's also hit safely in 19 of the 22 games since joining Milwaukee, including eight multi-hit performances.

Andrew Vaughn is UNREAL. #ThisIsMyCrew
pic.twitter.com/DCbelfd768

— ESPN Milwaukee (@ESPNMilwaukee) August 7, 2025

In all, he's gone 29-for-77 (.377) with four doubles, seven home runs, 28 RBI, 14 runs scored, and a 10:12 BB:K, good for a .476 wOBA and 215 wRC+ over that stretch. So can he keep it up?

He's registering a 93.4 mph average exit velocity, a 14.9 percent barrel rate, and 56.7 percent hard-hit rate, so it doesn't seem fluky; he simply looks locked in.

A high BABIP of .367 might indicate he's been a bit lucky, especially compared to a career BABIP of .287, and he's not going to hit .377 for the rest of the year, but he should continue to be productive nevertheless.

It feels like the former third-overall draft pick has been around forever, but he's still only 27 years old and suddenly playing for one of the hottest teams in baseball instead of the toothless offense he was playing with in Chicago.

Perhaps he's reenergized, coming into his prime, and finally living up to his first-round pedigree. The right-handed slugger is still available in about half of Yahoo! leagues, but should be worthy of a roster spot in most 12-team leagues.

Highest Batting Average Last Seven Days

Data through 8/6, minimum 13 at-bats

There are some interesting names here, and I was going to highlight Isaac Collins, but I decided to outline him below, so instead, we'll just start at the top.

JJ Bleday (.600 BA)

We're going to need to see a longer stretch of hitting from JJ Bleday before we can trust him on our season-long teams, but for now, he could be a viable DFS option while he's hot.

Bleday has two four-hit games in his last three contests, including two doubles and two home runs, along with seven RBI and five runs scored.

JJ BLEDAY BAY BAY 👏 pic.twitter.com/I89noe6TDF

— Athletics (@Athletics) August 5, 2025

The Athletics head to Baltimore for a three-game set, but then have six home games in a row (three vs. TB, three vs. LAA) in the hitter-friendly confines of Sutter Health Park.

The left-handed slugger has some surprising splits, slashing .354/.392/.583 (three HR) in 51 plate appearances against left-handed hurlers, but only .181/.284/.363 (seven HR) against right-handers in 197 PA, so be on the lookout for good matchups (i.e., LHP Cade Povich on Sunday), just make sure he's in the lineup before rolling with him.

(Update: Bleday went 0-for-2 after he entered the game on Thursday in the sixth inning)

Highest ISO Last Seven Days

Data through 8/6, minimum 13 at-bats

We all know Shea Langeliers can hit home runs, so we'll skip him (although he's hitting for average right now as well as seen in the previous graphic).

Daulton Varsho (.625 ISO)

Varsho has missed a lot of time this season due to injuries, and he hasn't hit for average when he's been on the field, hitting just .222 on the year through 28 games, but when he has put the bat on the ball, they've mostly gone for extra bases.

The 29-year-old has 24 hits in 108 at-bats in 2025, but only six of them have been singles. The left-handed slugger has six doubles, a triple, and 11 home runs this year, with three of those home runs coming in his last two games (along with 10 RBI).

467 FEET OFF THE UPPER DECK FOR DAULTON VARSHO 🤯 pic.twitter.com/qPeYDEItQt

— MLB (@MLB) August 6, 2025

Varsho has a 27-homer campaign to his name (2022), so there is definitely pop in that bat. A low contact rate (71.8 percent) and high chase rate (35.0 percent) could indicate this recent hot stretch won't last, but then again, his xwOBA (.354) is slightly higher than his actual wOBA (.348), so maybe his hits will simply start coming in the form of singles rather than extra bases.

He's rostered in just 12 percent of leagues for managers hoping to catch lightning in a bottle.

Jakob Marsee (.500 ISO)

You might forget that Jakob Marsee was the 2023 Arizona Fall League MVP, especially after hitting just .200 between Double-A and Triple-A in 2024, but he quietly put together a productive 2025 campaign for Triple-A Jacksonville before he was called up at the beginning of August for his MLB debut.

Although the .246 batting average didn't jump off the page, he hit 14 home runs while registering a .371 wOBA and 125 wRC+ in 98 games. Not to mention, he swiped 47 bases.

The 24-year-old stole 51 bases in 2024 and 46 in 2023, so this isn't a newfound skill. That is what could make him very interesting down the stretch for fantasy.

Jakob Marsee just keeps hitting... pic.twitter.com/r6RFqSfs68

— Marlins Radio Network (@MarlinsRadio) August 7, 2025

Through his first six games in the bigs, Marsee is 7-for-16 (.438) with three doubles, a triple, a home run, and a 6:6 BB:K. He's already stolen one base, but has also been caught stealing once, too, so it looks like he's not going to wait around to get comfortable before testing out his wheels.

Drawing as many walks as strikeouts means he could still get on base when his bat eventually cools, which also means the stolen bases should keep on coming.

He's only 10 percent rostered, but with his tools and with Miami playing better as of late, that number should be higher. If you're searching for steals at this juncture in the fantasy season, Marsee could be your guy.

(Update: Marsee went 2-for-4 with an RBI, a run scored, and a stolen base on Thursday)

Most Steals Last Seven Days

Data through 8/6

Note that catcher Ramirez has four steals in the past week, but I reserved a spot for him in one of the sections down below.

Josh Naylor (six SBs)

For a guy his size, Josh Naylor is surprisingly fleet of foot. Over the last week, not only has he been smacking home runs for his new club, the 28-year-old has been stealing bases. Six of them in the last week, to be exact, now with 21 of them for the season (previous high was 10).

At 98 percent rostered, you won't find him on waiver wires, and you were probably already using him frequently in DFS, but the steals add another dimension to his overall fantasy value.

(Update: Naylor went 0-for-2 on Thursday and departed the game with shoulder soreness, DTD)

xBA Underachiever

Data through 8/6

I normally provide a whole list of players here who are under- or overachieving in a particular stat, but there are a lot of the same names at the top of those lists, so I'm going to cherry-pick some that I found intriguing a bit lower on the lists.

Agustin Ramirez (.243 vs. .281)

Ramirez burst onto the major league scene in April, hitting .286 and smacking 11 extra-base hits over his first 14 games in the majors. He's continued to mash extra base hits, but has hit .236 in the 75 games since, leaving him with a .243 AVG for the year.

The good news is that the 23-year-old continues to hit the ball hard, and his expected batting average (xBA) is 38 points higher than his actual batting average, so he should remain productive over the rest of the season, and perhaps even go on a hot stretch here soon.

Not only that, as mentioned above, the 6-foot-1 backstop stole four bases in the last week, which is a very intriguing development, especially at the catcher position. The Dominican stole 22 bags last season in the minors, so he does have the ability.

Any fantasy manager looking for a catcher with the potential to add to the stolen base category should consider picking up Ramirez. He's just 66 percent rostered.

Agustín Ramírez will be considered a universal Top-5 catcher for dynasty by the end of the season.pic.twitter.com/5KlAjxNk9x

— Eric Cross (@EricCrossMLB) July 8, 2025

(Update: Ramirez went 1-for-5 with an RBI on Thursday)

xBA Overachiever

Isaac Collins (.292 vs. .261)

Surely, a big reason why the Brewers have been one of the best teams in baseball recently can be attributed to the success Collins has seen at the plate over the last two months.

Since June 12, Collins has hit .340 in 42 games. The former ninth-round draft pick was also recently named the NL Rookie of the Month for his performance in July, where he slashed .321/.411/.436 with three doubles, a pair of home runs, 11 RBI, 11 runs scored, and four steals in 23 games.

With a 78.3 percent contact rate and a low chase rate, he should continue to put the bat on the ball, but unfortunately, as a .253 hitter in the minors between Double and Triple-A (1333 PA), he could be a bit out over his skis right now.

The 28-year-old's xBA also indicates that, coming in at .261 on the season, while his actual BA sits at .292. The best of 2025 is probably behind him, so buyer beware.

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