MLB Sophomores: Who Will Improve, Who Will Stumble?

March 22, 2021

Marc Hulet analyzes five second-year MLB players that could see their 2021 sophomore results improve or plateau during the upcoming fantasy baseball season.

We all expect excellent rookie seasons from the most hyped prospects in baseball. But the reality is that some players just don’t hit their strides for a year or two. Other prospects start off strong but then fade away.

If we look back at 2015, Corey Seager, Miguel Sano, Carlos Correa, and Kris Bryant had top-10 wRC+ results (minimum 100 PAs). But other names among the top players included Mikie Mahtook (167 wRC+), Trayce Thompson (146 wRC+), Curt Casali (143 wRC+), and Greg Bird (137 wRC+). None of those players were able to replicate their early successes. That same year, other players didn’t fare so well in their first attempt to settle in at the MLB level: Byron Buxton (53 wRC+), Gio Urshela (65 wRC+), Max Muncy (80 wRC+), Joey Gallo (87 wRC+), J.T. Realmuto (89 wRC+), Jorge Soler (95 wRC+), and Eddie Rosario (97 wRC+). These seven players all went on to become solid (or better) fantasy contributors.

Today, I’m taking a look at five rookie players from the 2020 season — two pitchers and three hitters — in an effort to predict what we can reasonably expect from them during their sophomore campaigns. I’ve dug into last season’s numbers and also spent some time reviewing videos from this spring to help inform my decisions. There’s one name in particular that I’m extremely high on.

The Pitchers

Tejay Antone, RHP, Cincinnati Reds
Recommendation: Buy, Buy, Buy
Current ADP: 314

Antone might be this year’s Tony Gonsolin as a pitcher that is better than most people realize (I wrote about the Dodgers' pitcher last year at this time). And if he’s given a fair shot at starting, he could end up as the Reds’ third-best starter behind Luis Castillo and Sonny Gray. He made 13 MLB appearances in 2020, which included four starts. He stuck out 45 hitters while allowing 20 hits in 35.1 innings.

Antone has a power fastball and high spin rates on all three of his main offerings. His fastball averaged 95 mph in 2020. In his second start this spring, he was again sitting at 95 mph and regularly touching 97-98 mph. Last year, he allowed a .229 xBA with a .314 xSLG on the pitch but the whiff rate was just 19%. His slider was outstanding with a .154 xBA, a .290 xSLG, and a 46% whiff rate. His curveball was a distant third in terms of usage but it was also very good for Antone with a .098 xBA, a .160 xSLG, and a 35% whiff rate.

Overall, his 13% swinging-strike rate was better than Trevor Bauer, Clayton Kershaw, and Walker Buehler. It was also better than top 2020 rookie starters Triston McKenzie and Ian Anderson. His xBA of .167 and xSLG of .284 were among the top 3% and 6%, respectively. The fact that Antone is not being handed a guaranteed spot in the starting rotation by Cincinnati is almost criminal especially if the increased fastball velocity helps him see better results with that pitch. After pitching just 35.1 innings in 2020, the Reds will need to be cautious with him but it’s a similar story all around baseball in 2021. Even if he ends up pitching mostly in relief this year, he has a chance to produce elite results and acquire saves and holds.

Brady Singer, RHP, Kansas City Royals
Recommendation: Don't overpay hoping for a breakout
Current ADP: 263

Singer had a perfectly respectable freshman season at the major league level. In 12 starts, the young hurler struck out 61 batters while allowing 52 hits in 64.1 innings. He generated a .232 xBA and a 23% strikeout rate, which was slightly above the league average. Singer’s approach leads to a lot of ground-ball outs and he showed excellent command of the fastball in 2020.

But what happens if his command slips? As a two-pitch pitcher, he could be in trouble. Last season, Singer threw his sinker 57% of the time and his slider came in second at 37%. His other two pitches — a changeup and four-seam fastball — accounted for just under 6% of the pitches thrown. He allowed an xBA of .224 on his fastball with a modest whiff rate of 18% because it's an offering that's meant to be put in play. His slider had an xBA of .241 but the whiff rate jumped to 33%. The slider was a very good pitch but is it enough?

Singer is going to enter a new world in 2021. Teams will have detailed scouting reports on him as well as extensive videos to watch. And he’ll be expected to throw more innings after getting out of the fifth inning just five times last year. There’s also a big difference between 12 starts and 31 or 32. If Singer cannot add in a third reliable weapon, major league hitters are going to start having better success with him which could, in turn, limit his ceiling to more of a No. 4 starter. He could also soon be surpassed by more talented pitchers such as Daniel Lynch, Jackson Kowar, and Asa Lacy.

The Hitters

Ke'Bryan Hayes, 3B, Pittsburgh Pirates
Recommendation: Don't overpay expecting homers
Current ADP: 140

Hayes is a good baseball player. He could easily develop into a Gold Glove fielder at the hot corner and is ultra-athletic. He also has above-average speed for a third baseman. But Hayes is probably not a power hitter despite hitting five in 24 games during his MLB debut in 2020 — unless he continues to make more adjustments.

Hayes’ minor-league high in home runs was 10, which he managed in 2019 at triple-A with the juiced ball. In three pro seasons prior to that, he failed to surpass double digits in homers. He’s consistently done a nice job of hitting the ball with authority but his swing is geared to generate line drives, not home runs. Hayes’ ground-ball rates have always been well above 40% and sometimes near 50%. His HR/FB rate in the minors was well below 10%. If we look at 2020 at the MLB level, Hayes’ ground-ball rate was just shy of 48% so there was no improvement there. His HR/FB rate spiked to 25% which was very out of character for a player whose top HR/FB rate in the minors was 8.6%.

The power numbers are not the only thing that looks like a mirage. Hayes’ .376 batting average in 2020 was buoyed by a massive BABIP of .450. Still, he produced a strong barrel rate (9.2%) and a powerful hard-hit rate at 55% so his xBA of .294 feels about right. I foresee a 2021 season for Hayes that could including a .270-.290 batting average, 30-40 doubles, 15+ home runs, and double-digit steals. If we see a positive shift in the batted ball profile, the home runs could increase. Hayes’ ADP currently sits around 140 as the 19th-ranked third baseman. That’s a very reasonable ranking for a strong all-around hitter’s profile that’s light on power.

Luis Robert, OF, Chicago White Sox
Recommendation: Target in dynasty for 2022 breakout
Current ADP: 38

Robert’s 2020 season didn’t go as well as expected. An early-season favorite for rookie of the year, he ended the campaign with a 101 wRC+ and a 32% strikeout rate. He started off well enough (.297 batting average over the first two months) but then MLB pitchers realized that they didn’t need to throw him strikes and he hit just .136 with one extra-base hit the rest of the way.

We can see how aggressive Robert was during the season by looking at his swing rates. He swung at the first pitch he saw 54% of the time, which was well above the league-average of 29%. And he was often fooled by pitches in the strike zone as witnessed by his zone swing rate of 81% (league average is 67%) and his zone contact rate at 68% (league average is 82%). Interestingly, the man with the lightning-quick bat struggled against fastballs and hit just .204. He was more successful against breaking balls at .271 and off-speed pitches at .231. The numbers suggest Robert was being thrown a lot of fastballs outside the strike zone and seeing more soft stuff in the zone.

When he made contact, things went a long way. He had a strong barrel rate and an above-average launch angle. His exit velocity and hard-hit rates were lower than you’d expect because he was making contact with pitcher’s pitches. Robert is still an electric player with the ability to hit at least 20+ home runs and steal 20+ bases but he has to make the pitchers come to him. Now might be the time to try to pry him away from your dynasty league opponents; I think he’s smart enough and skilled enough to learn from his mistakes although he’ll never be called “patient.” It also might take another year to fully temper his aggressive nature to the point where he becomes an elite bat because these tendencies aren't easy to change overnight.

Mauricio Dubon, CF, San Francisco Giants
Recommendation: Excellent buy-low candidate
Current ADP: 359

Dubon is a player that was very likely hurt by the truncated season in 2020. He got off to a tepid start to the season by hitting .238 with a 32% strikeout rate and a 54 wRC+ over the first month of the season. But he showed improvements each month and, in the final month of the season, hit .273 with an 18% strikeout rate and a 122 wRC+. He even produced more power as the year progressed. He had an ISO rate of .048 in his first month but ended with a .182 rate over the final month of the year.

Entering the 2020 season, Dubon was seen as a player capable of hitting for a solid batting average while providing some steals and surprising gap pop. Aside from the speed, that’s exactly what we saw from the young centerfielder in his final month of 2020 and what I expect to see more of in 2021. If we dig a little deeper into Dubon’s 2020 season, we can see that he was very strong against fastballs but really struggled with breaking balls. He was held hitless against them in July. In August, though, he was up to a .174 average (.189 xBA). Then in September, he improved to a .231 average (.294 xBA).   

Dubon isn’t a power hitter. He’ll never be a power hitter. But he did hit 24 home runs between triple-A and the majors in 2019 while enjoying the juiced ball. He’s seen his line-drive rates increase in recent years as he’s matured physically. His 2020 launch angle was above-average at 17%. I believe a .270-.280 average, with 30 doubles, 12-15 home runs, and 10-15 steals is possible.

Dubon is likely going to be the Giants’ centerfielder in 2021. There is a smaller chance that he could end up in a super-utility role as he’s seen time at four different positions so far this spring. Either way, he should play every day or close to it and the improvements made during the 2020 season hint at more offensive potential to come. With good outfielders always in short supply, this young hitter deserves your attention.

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