The Seattle Mariners have put their closer, right-hander Hunter Strickland, on the 10-day injured list because of a right lat strain.
Strickland gave up a winning three-run home run to Boston pinch hitter Mitch Moreland in the top of the ninth inning Friday night.
After the game, he said he was feeling discomfort in his right shoulder.
Right-hander David McKay was called up to take Strickland's place in the bullpen.
Strickland signed with the Mariners on a one-year, $1.3 million deal in the offseason, after spending his first five years in the majors with the San Francisco Giants.