CHICAGO -- Former American League Rookie of the Year Michael Fulmer, returning from Tommy John surgery, was brought up from the minor leagues Sunday when the Boston Red Sox placed right-hander Richard Fitts on the 15-day injured list with a right pectoral strain.

A 32-year-old right-hander, Fulmer has not pitched in the big leagues since 2023 with the Chicago Cubs. He had Tommy John revision surgery on Oct. 18, 2023, signed a minor league contract with Boston the following Feb. 2 and did not pitch last year.

Fulmer had a 0.79 ERA in five spring training appearances for the Red Sox, striking out 12 and walking three in 11 innings. He had a 3.09 ERA in two starts and one relief appearance for Triple-A Worcester, striking out 18 and walking six in 11 innings. His four-seam fastball averaged 92.4 mph.

He won the 2016 AL Rookie of the Year with the Detroit Tigers, had Tommy John surgery on March 27, 2019, and returned to the major leagues on July 27, 2020, just after the start of the pandemic-shortened season.

Fulmer is 37-50 with a 3.94 ERA in 90 starts and 172 relief appearances for the Tigers (2016-22), Twins (2022) and Cubs (2023).

Fulmer's contract was selected from Worcester. Red Sox manager Alex Cora said he expects to use Fulmer out of the bullpen.

Fitts will undergo an MRI on Monday to determine the extent of his injury, Cora said. The 25-year-old left Saturday's game against the White Sox with shoulder discomfort as he was facing Miguel Vargas, Chicago's first hitter in the sixth inning.

Making his seventh big league start, Fitts had a 2-0 lead and allowed two hits. He was in position for his first major league win when he was replaced by Zack Kelly with a 2-2 count on Vargas. Vargas walked, and two batters later Luis Robert Jr. hit a two-run homer,

Chicago went on to win 3-2 on pinch-hitter Brooks Baldwin's RBI single in the ninth.

Fitts has a 2.39 ERA in seven starts for the Red Sox over two seasons. He is 0-2 with a 3.18 ERA this year.

Fulmer has a contract paying a $1.5 million salary while in the major leagues and $180,000 while in the minors.

He can earn $2 million in performance bonuses for innings and $500,000 for relief appearances. Fulmer would get $50,000 each for 75, 80, 85, 90 and 95 innings, $100,000 apiece for 100, 110, 120, 130 and 140, and $250,000 each for 150, 160, 170, 180 and 190. He would earn $100,000 each for 40, 45, 50, 55 and 60 relief appearances.