White Sox Players Most Likely to Regress in 2026

Earlier this week, I cautioned my fellow Chicago White Sox fans about setting expectations too high for the 2026 season.

While most of the fanbase has adopted a more tempered mindset heading into free agency — Jerry Reinsdorf’s track record has essentially forced that — it’s still easy to get overly optimistic about the homegrown talent that sparked hope in 2025.

When a young player flashes, the natural assumption is that another year of development automatically leads to even more production. But that’s not always how this works. Development is not linear, and regression is always lurking. That’s true in all sports, but especially in a fickle game like baseball.

So as we look ahead to 2026, here are the three White Sox players who I believe are most likely to experience some level of regression at the MLB level.

Colson Montgomery

No breakout season was more unexpected in 2025 than Colson Montgomery’s. The rookie shortstop struggled to earn his place in the minors early in the year before a midseason reset completely altered the trajectory of his career.

Montgomery made his MLB debut on July 4 and, after switching to a torpedo bat post–All-Star break, launched 21 home runs in just 71 games. Just like that, the former first-round pick became a fan favorite and gave White Sox fans hope that he could be both the shortstop of the future and an All-Star in the making.

The defense was better than expected and the power was undeniable. Montgomery posted 2.7 fWAR in his limited action — a pace that would have put him above 5.5 fWAR and 40+ home runs over a full season.

White Sox fans may not be expecting that level of production in 2026, but plenty are still projecting 30 home runs and an OPS around the .840 he delivered as a rookie.

I loved watching Montgomery as much as anyone, but his offensive profile gives us reasons to believe a step backward is more likely than a step forward.

The power is legit. Montgomery didn’t hit wall-scrapers — he flirted with the concourse at Rate Field on several occasions. His bat speed is comparable to Kyle Schwarber and Aaron Judge. Chicago needs that pop in the lineup. But his swing decisions raise concern.

Montgomery had a 31.5 percent whiff rate, 29.2 percent strikeout rate, and a clear vulnerability to off-speed pitches below the zone as a rookie. He often chased the same pitch in the same location, and got the same result. Even hitters with elite bat speed and raw talent stall out when they fall into that cycle.

Maybe Montgomery breaks out of it quickly. But the White Sox will need to sharpen his approach and pitch recognition skills.

The power isn't going anywhere in 2026, but it’s possible we see something closer to 20–25 homers with an OBP that suffers as pitchers adjust to him. I’m still bullish on Colson Montgomery long term — but expecting another leap after a magical rookie season might be setting the bar too high.

Lenyn Sosa

I’m out on Lenyn Sosa. I've been on the record with that for quite some time now, even after a career year in 2025. Sosa's swing-decision issues are significantly worse than Montgomery’s, and the underlying metrics point to danger ahead.

Sosa now has over 1,000 major-league at-bats with only 36 walks in his entire career. Even in a season where he led the White Sox in hits, home runs, and RBIs, his offensive value was dragged down by a poor on-base percentage and overall lack of plate discipline.

The strikeout rate is bad. But what’s worse is how often he gets himself out with soft contact because he expands the zone and refuses to take walks. Montgomery at least takes his freebies. Sosa simply does not.

He had the second-worst walk rate in MLB and was in the 3rd percentile in chase rate.

2025 felt like the season where Sosa finally put it all together, yet his OPS+ was just 101, barely league average.

Montgomery has the pop that produces consistent loud contact with elite bat speed. Sosa does not. In 2025, he was in the 59th percentile in bat speed and 52nd percentile in hard-hit rate. His slugging numbers were built primarily on ideal launch angle, not raw power.

Pair that with no defensive home — and subpar defense at multiple spots — and it’s easy to see 2026 being the year Sosa crashes back to earth.

His 2025 production looks far more like an anomoly than a sign of what's to come. The White Sox would be wise to explore the trade market while his value is artificially elevated. Sell the fool’s gold if you can.

Mike Vasil

Mike Vasil was one of the most remarkable finds of the 2025 season. Claimed off waivers just days before Opening Day, he ended up throwing over 100 innings with a sparkling 2.50 ERA, becoming one of the most valuable players on the team. He led the White Sox in win probability added (WPA).

Vasil thrived in every role thrown at him — high-leverage relief, multi-inning long relief, and even the occasional spot start. He did it all well and brought an infectious personality to the ballpark that made him one of the more popular guys in the clubhouse.

A great find, and a player that will have a role for the White Sox moving forward. Vasil is a big leaguer. He induced enough ground balls and limited loud contact well enough to stick, but regression still feels likely when you look at the underlying data.

For starters, his expected ERA sat at 4.06 — a massive gap from the surface-level 2.50. 

He was also in the 3rd-percentile in chase rate. Hitters rarely expanded the zone against him, suggesting his stuff either wasn’t fooling anyone or his pitches were uncompetitive enough that hitters had no reason to get themselves out.

Vasil issued 52 walks in 101 innings. Control wasn't a top of mind concern until I looked at the numbers, but that's an issue that needs to be fixed — and typically a recipe for more runs allowed. Vasil worked through traffic well in 2025, but that batted ball luck rarely repeats.

If he doesn’t clean up the walks, his ERA is going to inflate.

Does Vasil have a clear role in 2026? Absolutely. But will he once again be the most valuable pitcher on the roster? I wouldn’t bet on it — nor should the White Sox want that.