Finding sleepers can be one of the most satisfying things in fantasy baseball. Picking a player late in drafts who outperforms expectations is half the fun of playing fantasy baseball. In fact, it is a requirement to build a championship team. Finding value late is essential to a successful draft strategy. The article below identifies three first base sleepers going late in drafts that could far outperform their current expectation.
Fantasy Baseball First Base Sleepers
Tyler Soderstrom – ATH
If there is one player I am out acquiring in every league, it is Tyler Soderstrom. In keeper leagues, I am trading away first basemen like Bryce Harper and Triston Casas just so I can prioritize adding Tyler Soderstrom. Does that mean Soderstrom is going to be better than Harper? Probably not, but there is extreme value with Soderstrom. While Harper is being drafted 20th overall, Soderstrom is not even going inside of the top 20 at the position. Going as 1B28 in drafts at pick 329, Soderstrom is one of the biggest sleepers in fantasy baseball for 2025.
The Athletics took Soderstrom 26th overall in the 2020 draft. Originally drafted as a catcher, Soderstrom has shifted over to first base in recent seasons due to Shea Langeliers locking down the primary catcher role. Soderstrom was always viewed as a bat-first prospect regardless of position. He followed up 12 home runs in his debut season with 29 in 2022 and then another 24 in 2023. There is 30+ home run upside in his bat thanks to his big 6’2” frame and excellent batted ball data.
Soderstrom’s power has long been acknowledged. His power is not what is pushing him down to 28th amongst first baseman in fantasy baseball drafts. The issue and concern lies with his hit tool. Soderstrom has battled strikeout issues throughout his professional career. The lowest rate Soderstrom has posted in any season was 24% back in 2021. With suspect contact skills and plate discipline, the risk is obvious. Soderstrom hit just .160 in his 45-game Major League debut in 2023 and then just .233 last season. So, why is 2025 going to be any different?
Not every prospect that comes up from the Minor Leagues is going to find instant success. Players struggle to adapt to Major League pitching and Soderstrom is still just 23 years old and still developing. What fantasy managers can look for are tangible improvements. Early on, 2024 looked like more of the same from Soderstrom whose strikeout rate sat above 41% on June 5. Then, it was as if a switch flipped. All of a sudden, Soderstrom stopped striking out. In his final 158 plate appearances, Soderstrom struck out just 19% of the time. His numbers drastically improved as he hit .252/.316/.469 the rest of the way. His 600 PA home run pace over that period was 31 bombs.
Being able to draft a player with as much power upside as Soderstrom so late in drafts is rare. There were 14 hitters with 200+ plate appearances last year that met the following criteria: Swing speed greater than 74 mph, barrel rate greater than 14%, and an average exit velocity above 91 mph. Giancarlo Stanton, Aaron Judge, Kyle Schwarber, Shohei Ohtani, Austin Riley, Fernando Tatis Jr, Soto, Oneil Cruz, Matt Wallner (sleeper?), Yordan Alvarez, Helito Ramos, Bobby Witt Jr, and yes of course, Tyler Soderstrom. That is primarily a list of the game’s best power hitters and a pretty good list to be a part of.
Soderstrom now will get to play his home games in a Triple-A ballpark for the 2025 season. For all the hype Lawrence Butler is getting, Soderstrom deserves some appreciation as well. .250 with 35 home runs is not out of the range of possibilities for Soderstrom who should be being drafted much higher than he currently is.
Nolan Schanuel – LAA
The Angels rushing prospects through their system can alter the perception of that player in the minds of fantasy managers. Take Nolan Schanuel for example. A first-round pick for the Angels, Schanuel appeared in just 22 Minor League games before being promoted to the Major Leagues. Certainly, a player moving up that quickly has to be an elite talent. Then, after the lack of Minor League experience catches up to him, fantasy managers are left disappointed and with a sour taste in their mouths. This is to no fault of Schanuel who is still developing and learning how to handle Major League pitching. Now with a full season under his belt, Schanuel is not sought after by anybody in the fantasy community. He is going as 1B26 in drafts, which is far too low for a player about to enter his second full professional season.
Starting with what we already know, Schanuel has some of the best contact skills in all of baseball. From the time he was drafted, Schanuel has posted elite whiff rates while hardly striking out. His walk rate has consistently sat above 10% giving fantasy managers a solid base for their on-base percentage. In his rookie season, his whiff rate ranked in the 96th percentile with his chase rate ranking in the 91st percentile. There are not many rookies that come as polished as Schanuel. The other good part of Schanuel’s game is his ability to hit line drives. Schanuel hits tons of line drives to all parts of the field which should result in better BABIP luck than he saw in 2024.
The issue is a lack of power. Home runs are crucial at the first base position and Schanuel hit just 13 last year. The bright side is that his HR/FB rate doubled from 2023 to 2024. Standing at 6’4”, Schanuel should be able to generate significant pop. Despite him prioritizing contact over power, there remains upside on the chance he can blend those two skills.
This pick is not as obvious as Soderstrom. With Schanuel, fantasy managers have a chance to take a shot on a 23-year-old 6’4” first baseman entering his second season. The best part is that there is no risk in taking him. His draft price is so low, and his floor is so stable that fantasy managers are guaranteed to walk away with at least a starting player who is going to post excellent on-base numbers. The hope is that he can work his way into more power. Even if Schanuel just can get up to the 20 home run mark, he could turn into a significant fantasy asset. At pick 318, lock in an everyday Major League starter and add some upside to your fantasy team. Schanuel is a perfect sleeper pick without the risk.
Ryan Mountcastle – 1B, BAL
Identifying specific categorical upside late in drafts is a great strategy for picking sleepers. For Soderstrom, it was power. His power is an outlier for the players going around him in drafts. For Schanuel, it is elite contact rates that we rarely see from players his age. Ryan Mountcastle falls into a similar power bucket as Soderstrom. Just a few years ago, Mountcastle hit 33 home runs as a rookie. Although his home run totals have lagged off in the past few seasons, there is still big-time power upside here. In early drafts, Mountcastle is going as 1B21 outside of the top 250 picks. This is the perfect low-risk price to take a player with significant upside.
Coming through Baltimore’s system, the biggest debate with Mountcastle was how well his hit tool would translate to the Major Leagues. Mountcaslte struggled to keep his whiff rate in check early in his career leading to high strikeout rates and mediocre batting averages. Although his power has ticked down the last several years, Mountcastle has made significant improvements to his hit tool. After whiffing 31.6% of the time his rookie season, Mountcastle whiffed just 25.1% last year. His zone contact rate has improved gradually over the course of his career turning what was once a weakness into a subtle strength. This combined with his ability to spray the ball to all fields has resulted in strong batting averages that fantasy managers should view as stable.
The big issue over the past few seasons has been the decline in home runs. Mountcastle has gone from 33 home runs in 2021 all the way down to 13 last year. If you have been keeping up with the Fantrax offseason articles, you may have seen one identifying players likely to see their home run totals increase in 2025. Mountcastle was an easy pick for this. While I encourage you to check that article out, the synopsis is that Mountcastle was extremely unlucky on the barrels he hit last season. The wall in Camden Yards moving back in along with better luck should help provide a huge boost to his home run totals.
There were eight players in baseball last year with a swing speed above 74 mph, an average exit velocity over 90 mph, and a sweet spot percentage above 36%. Bryce Harper, Aaron Judge, Byron Buxton, Shohei Ohtani, Austin Rilye, Matt Wallner (Wallner again!), Riley Greene, and the obvious inclusion of Ryan Mountcaslte. Fantasy managers should not get hung up on Mountcastle’s 13 home runs from last season. He has significant power upside and should see much better results in 2025. His draft price is the highest of the three sleeper picks but a worthy option to fill your 1B slot.
Who are your favorite first base sleepers for 2025? For more of the great fantasy baseball rankings and analysis you’ve come to expect from FantraxHQ, check out our full 2025 Fantasy Baseball Draft Kit! We’re here for you all the way up until Opening Day and then on into your championship run.