It’s been an eventful few days for the White Sox on the free agent market.
After inking Japanese power-hitting first baseman Munetaka Murakami to a $34 million contract on Sunday, the White Sox bolstered the pitching staff Tuesday with the signing of left-hander Sean Newcomb. Coming off perhaps the best season of his nine-year MLB career, Newcomb’s deal is for one year and $4.5 million.
To make room for Newcomb, the White Sox designated left-handed pitcher Ryan Rolison for assignment. Rolison was recently claimed off waivers by the White Sox after posting a 7.02 ERA with the Colorado Rockies. The White Sox 40-man roster remains at 40.
What Sean Newcomb brings to the White Sox
Athletics pitcher Sean Newcomb (31) throws against the Houston Astros at Daikin Park. | Troy Taormina-Imagn Images
Newcomb, 32, is a 6-foot-5, 255-pound left-handed pitcher who split time between the Boston Red Sox and Athletics during the 2025 season. He was the 15th overall pick by the Los Angeles Angels in 2014, but made his MLB debut with the Atlanta Braves and had a brief stint with the Chicago Cubs.
Newcomb began the 2025 season as a starting pitcher for the Red Sox. Across five starts, he allowed 32 hits and 11 runs while striking out 27 batters and walking 11 in 22.1 innings. That stretch included a four-inning outing against the White Sox on April 11, when he gave up two earned runs and was credited with the loss.
But for most of the season, Newcomb served as a multi-inning reliever and was often utilized in high-leverage situations. And when pitching out of the bullpen, Newcomb was among MLB’s best.
From April 27 until season’s end, Newcomb ranked sixth among MLB pitchers (minimum 70 innings) with a 2.19 ERA, behind only Nathan Eovaldi, Chris Sale, Trevor Rogers, and Cy Young winners Paul Skenes and Tarik Skubal. Newcomb also ranked 14th in FIP and 45th in WHIP during that stretch.
After being traded on May 27 to the Athletics for cash considerations, Newcomb finished the year with 1.7 wins above replacement across 92.1 innings, per FanGraphs, which was the second-best mark of his career. His career-high fWAR of 1.9 came in 2018 on a much larger sample of 164 innings as a starter with the Atlanta Braves.
He’s coming off a season with the lowest walk rate of his career at 7.9%, which ranked 81st among MLB pitchers with at least 90 innings in 2025. He also ranked 52nd with a 23.3% strikeout rate, just two spots behind White Sox All-Star Shane Smith.
Newcomb notably cut down on his fastball usage, throwing it a career-low 29.9% of the time in 2025 with an average velocity of 93.3 mph. He fastball previously accounted for 47% or more of his pitches each year of his career, including three seasons of 62% or more. He also decreased his curveball usage by roughly 10%, opting for a heavier dose of cutters, sinkers and changeups.
While he’s made 65 career starts in the big leagues and the White Sox could still use a starting pitcher, Newcomb’s success pitching out of the bullpen in 2025 suggests he might best help the White Sox as their top left-handed leverage reliever.
Related stories on the Chicago White SoxWhite Sox Sign Japanese Slugger Munetaka MurakamiWhite Sox Hire Carlos Rodriguez As Assistant General ManagerWhite Sox Trade For Outfielder Tristan PetersWhite Sox Announce Full 2026 Major League Coaching Staff