Infielder Michael Chavis was recalled from the team's alternate site to fill Martinez's spot on the roster.
Martinez, 33, has been one of baseball's best hitters in his career. Between 2015 and 2018 he ripped 148 homers and 404 RBI, numbers that would be even higher had he not missed 42 games in 2016 and 43 games in 2017 because of injuries.
He proved as much in the 2018 campaign, when he hit .330 with 43 homers and 130 RBI, making a legitimate push for both an MVP award and Triple Crown. While he didn't accomplish either, he did win Silver Slugger awards as both an outfielder and designated hitter. He also won a title with the Red Sox.
He continued on that torrid pace in 2019, hitting .304 with 36 homers and 105 RBI. He did struggle in 2020, hitting .213 with seven homers and 27 RBI in 54 games, though the coronavirus-shortened season was an odd one on a number of fronts.
Martinez is 13-for-30 to begin the season with two home runs and 12 RBI.
The three-time All-Star isn't replaceable for Boston, though Franchy Cordero and Bobby Dalbec should see an uptick in playing time while he's out.