Hanrahan entered a 5-4 game in the ninth looking for his fifth save of the year. But Brian Dozier homered with one out to tie it and, one out later, on Hanrahan's first pitch to Justin Morneau, Red Sox manager John Farrell came jogging out of the dugout with the training staff.
Hanrahan left the game and was relieved by Clayton Mortensen.
The team announced in the 11th inning that Hanrahan had tightness in his throwing arm and will be re-evaluated Tuesday. Earlier in the day, the Red Sox placed Andrew Bailey on the disabled list with right biceps soreness.