With most spots seemingly spoken for, 30-year-old Tyson Miller’s advanced metrics and Cactus League debut suggest he could quietly force his way into the White Sox bullpen picture.
With some of the offseason moves that have been made this winter, there's little room in the Chicago White Sox bullpen for spring training breakouts.
Chicago signed Seranthony Dominguez to be the team's next closer. They also locked up Sean Newcomb, who was widely considered to be one of the top left-handed relievers on the free-agent market.
Finally, there was a trade with the Boston Red Sox for righty flamethrower Jordan Hicks. And while that deal was more about taking on Hicks's contract to upgrade pitching prospects and bring in David Sandlin to the organization, the White Sox are still on the hook for $8.5 million to Hicks this season. They're not paying somebody that kind of money to be in Triple-A.
That right there is three spots in the bullpen locked up. And other White Sox pitchers like Jordan Leasure, Mike Vasil, and Grant Taylor feel like locks in their own right, given the success they had in 2025 and their versatility to be stretched out for multiple innings or pitch in high-leverage spots.
Like I said, not much room for a breakout candidate — especially when you consider the roster math of needing to keep left-handed pitchers around, and the fact that the White Sox made two selections during the Rule 5 Draft back in December.
Chicago will want to keep an open mind to both Jedixson Paez and Alexander Alberto breaking camp with the team.
But if there is someone to watch out for — if there is a non-roster invitee who could make the White Sox roster — many people are looking at left-handed pitcher Ryan Borucki, a local product from Mundelein, Illinois, and a lifelong White Sox fan.
I'm looking more at 30-year-old righty Tyson Miller. Miller has had recent MLB success and really impressed in his Cactus League debut for the White Sox on Friday.
Miller, 30, was a fourth-round pick by the Chicago Cubs in the 2016 MLB Draft. While he’s been with six different organizations during his pro career, he was most recently back with the Cubs in the minor leagues in 2025.
Miller’s last MLB action came in 2024, when he made 58 appearances out of the bullpen, throwing 62 innings between the Cubs and the Seattle Mariners. He went 5–1 with a 2.32 ERA and posted an impressive 0.81 WHIP.
A left hip impingement landed Miller on the injured list before the 2025 season began, and he struggled to regain momentum. He never looked fully comfortable once he returned to minor league play, and he was back on the shelf multiple times over the course of the season.
Miller is now with the White Sox after joining the organization on a minor league deal this winter.
He got to face his former team on Friday, taking on the heart of the Cubs' batting order and retiring them in order. Miller got third baseman Alex Bregman to ground out. He struck out Seiya Suzuki, then finished things off with a lazy flyout to center field against Miguel Amaya.
Miller isn't a hard thrower. He never has been — but he doesn't have to be. On Friday, his average four-seam fastball velocity was just 88.2 mph. He worked with a two-pitch mix, throwing a pretty even split between his fastball and his sweeper, which comes in at 78.3 mph. But at this stage of spring training, velocity really isn't my concern. Pitch shape and quality are more important.
Miller had great tunneling between his fastball and his sweeper on Friday, with legitimate horizontal separation between the two pitches — both of which graded above average.
Even sitting sub-90, the fastball had a whiff percentage of 66.7% on Friday — excellent, even in a small sample size. The sweeper had almost 16 inches of horizontal movement.
As velocity ticks up the closer we get to the regular season, Miller's stuff should only improve. But he's already demonstrating the ability to beat hitters with movement and location.
This is exactly what he did the last time he had MLB success in 2024. Miller was well above average in chase rate, hard-hit percentage, and average exit velocity during that 2024 season, and both his fastball and his sweeper were equally effective.
When he has his control, the metrics show he can get outs.
It's a really unique profile compared to what the White Sox currently have in the bullpen, and it could be the thing that separates him from other bubble contenders if a spot opens up.