Ahead of Sunday’s regular-season finale at Tropicana Field against the Chicago Cubs, the Boston Red Sox made several roster moves, including placing two key contributors in utility man Mickey Gasper and reliever Tyron Guerrero on the injured list. 

The move to the injured list was expected for the 30-year-old Gasper, who suffered what manager Chad Tracy called a “significant” right bicep injury in game one of Friday’s doubleheader against the Cubs. 

The loss of Gasper is a massive blow for a Red Sox offense that has struggled in September. The 30-year-old New Hampshire native was undoubtedly in the best stretch of play of his big-league career, hitting .272/.427/.691/.118 with 10 home runs since being recalled from Triple-A on Aug. 17. Overall, Gasper is hitting .251/.357/.466/.823 with 10 home runs, nine doubles, and one triple while driving in 24 runs in 67 games. 

With Masataka Yoshida on the shelf, Gasper was set to take on a massive role in the Boston lineup in the postseason. Now, the injury is likely to end his season. 

In a somewhat shocking move, the 35-year-old flamethrower lands on the injured list with a right shoulder strain. The move comes just one week after he returned from the same injury. 

Guerrero, who last appeared in the major leagues in 2019, has been a key piece in the Red Sox bullpen after signing a minor league deal with the team in the offseason. 

After posting a 5.77 ERA in 113 appearances in his first three seasons in the big leagues, walking 5.7 batters per nine innings. Guerrero has unlocked something working with Boston pitching coach Andrew Bailey, posting a 3.10 ERA in 40.2 innings, cutting his walk rate to just 1.77 batters per nine innings, the 12th-lowest mark among all relievers with at least 40 innings. 

He will now miss at least the first two rounds of the postseason. 

Boston has recalled utility man Nate Eaton and reliever Wyatt Olds to replace Gasper and Guerrero on the active roster. 

The 29-year-old utility man rejoins the Red Sox just four days after being optioned when the team activated center fielder Ceddanne Rafaela from the injured list. 

Eaton saw limited playing time after being recalled to replace the injured Rafaela on the active roster, appearing in parts of nine games, going 3-for-16 at the plate. 

After a strong performance for Great Britain at the World Baseball Classic in March, Eaton has seen little action at the major league level in 2026, playing just 23 games for the Red Sox, hitting .146/.293/.250/.543. 

The 27-year-old right-hander returns to Boston after being optioned when the team first activated Guerrero from the IL a week ago. In two stints with the major league team in 2026, Olds posted a 1.20 ERA in 13 appearances spanning 15 innings. 

His strong performance in Guerrero’s stead made him an intriguing bullpen option for the postseason; it now appears he’s in the driver's seat to make that initial playoff roster. 

After escaping a Nor’easter in New England, the Red Sox will host the Cubs in the regular season finale from Tropicana Field on Sunday afternoon. Tanner Houck (0-0, 0.00 ERA) will make his return to a big-league mound, getting the start for Boston opposite left-hander Shota Imanaga for Chicago. First pitch is set for 3:05 p.m. ET. 

Houck hasn't pitched in the big leagues since early 2025 after going down with Tommy John surgery.