Playing the outfield because Boston finished the regular season in Washington, an NL park where the DH is not used, Martinez slipped on second base while taking his position between innings. He remained in the game for a half-inning before he was replaced by a pinch hitter.
Manager Alex Cora said Monday that Martinez was getting treatment and the Red Sox would see how his ankle responds. The four-time All-Star batted .286 with 28 homers and 99 RBIs this season.
The Yankees added outfielder Greg Allen to their roster, along with Rob Brantly as a third catcher. Left-hander Andrew Heaney and right-hander Brody Koerner were designated for assignment to open roster spots.
With ace Gerrit Cole on the mound, Kyle Higashioka will be behind the plate. Manager Aaron Boone said starting catcher Gary Sánchez will not be his designated hitter, leaving Sánchez to begin the game on the bench along with Brantly, who was 3 for 20 in six games with the Yankees this season.
Allen is speedy and could be used as a pinch runner.