Newcomb, 32, was a first-round pick by the Angels in 2012 and spent years in the top 100 in the minors. The left-hander made his big league debut with Atlanta in 2017, after previously coming over as part of the transfer of Andrelton Simmons. He spent the first two seasons of his career as a rotation player, posting a 4.06 ERA (103 ERA+) and a 4.16 FIP, giving him the look of a decent back-end starter. Unfortunately, early season struggles in 2019 led to him being demoted to Triple-A and moving to a bullpen role upon his return. He started four games for the Braves in 2020, but also struggled during those starts, ultimately not starting another game for the team before being designated for assignment by the club.
The left-hander was traded to the Cubs shortly after his DFA and moved to the bullpen for the club, but struggled to get things in order over the next few seasons. He pitched an atrocious 6.61 ERA in 47 2/3 innings of work at the Major League level between the Cubs and A’s over the next three seasons, mainly held back by a whopping 15.0% walk rate. In January, Newcomb joined the Red Sox on a minor league deal and found a way back into a big league rotation job between a strong performance in spring training coupled with injuries to rotation players like Lucas Giolito and Brayan Bello that left them off the opening day roster.
Newcomb’s performances were once added to the rotation as a mixed bag. He made five starts for the Red Sox and posted a mediocre 4.43 ERA, but did so with strong periphery. He struck out 25.7% of his opponents while walking 10.5%. After moving to the bullpen, he posted a much stronger 3.38 ERA in seven relief appearances for Boston, although his strikeout rate dropped during those appearances. That led the Red Sox to designate him for assignment in late May, and he was traded back to the A’s shortly thereafter.
The left-hander remained with the Athletics for the rest of the 2025 season and did very well for himself with the club. In a full-time relief role for the A’s, Newcomb pitched to an eye-popping 1.75 ERA with a 2.69 FIP in 51 1/3 innings of work. That stellar performance was backed up by strong periphery, as he struck out 24.9% of his opponents, walked just 7.0% and posted a strong 48.9% groundball rate. His 3.22 SIERA in West Sacramento would be good for 44th among relievers with at least 50 innings of work last year if separated from his time in Boston. He would also rank fifth by ERA and 18th by FIP.
That performance is more than strong enough to provide Newcomb with a solid one-year guarantee to become a lefty bullpen arm, and the 32-year-old could likely have secured a similar dollar amount from a more competitive team before 2026 on contracts offered this season to comparable lefties like Caleb Thielbar, who rejoined the Cubs earlier this month with a $5 million guarantee. That said, those contenders would likely have wanted to keep Newcomb in a full-time bullpen role. The White Sox, on the other hand, have no expectations of contention in 2026 and therefore can afford to offer Newcomb the opportunity to earn a rotation spot this spring.
Anthony Kay, a fellow offseason signing, joins Shane Smith and Davis Martin in the first three rotation spots for the White Sox this year. That leaves Newcomb to compete with the likes of Sean Burke, Jonathan Cannon and Chris Murphy for the final two spots in the club’s rotation. It wouldn’t be a shock to see Newcomb move into that role, though it’s certainly possible he could also be used in a late-inning role, as the Sox bullpen currently only has Mike Vasil and Jordan Leasure as leverage options, with Tyler Gilbert as the leftmost option.
As for Rolison, the southpaw was claimed off waivers from Atlanta earlier this month. Rolison made his MLB debut this past year as a member of the Rockies, but struggled mightily this year, posting a 7.02 ERA in 42 1/3 innings of work at the big league level for Colorado. The left-hander will now be put through the waiver wire again unless the Sox make a deal involving Rolison before then. Should he clear waivers, Rolison believes he will be sent straight to Triple-A as Chicago is not on the roster heading into the 2026 season.
#Veteran #lefty #Sean #Newcomb #signs #White #Sox #chance #start