Martinez is out of the lineup for Monday's game against the Red Sox.
Red Sox manager Alex Cora provided no indication that Martinez's absence from the lineup in Sunday's 5-2 win against the Rangers was injury-related, but the fact that the 35-year-old is now on the bench for a second day in a row suggests that a physical issue could be in play. An explanation behind Martinez's back-to-back days off could come later Monday, but Tommy Pham will get another turn as Boston's designated hitter in his stead in any event.