Red Sox pitcher John Lackey, who on Saturday made his first start since the 2011 season due to recovery from Tommy John surgery, left the game against the Blue Jays with a right bicep strain.
Lackey exited the contest with one out in the bottom of the fifth, on a 3-2 count to Jose Reyes. He left the field under his own power, but dangling his right arm by his side and holding the area around his elbow.
The 34-year-old right-hander finished 2011 with a 12-12 record and a 6.41 earned run average for the Red Sox.
Alfredo Aceves took over on the mound. He finished the contest allowing three hits and as many runs with five strikeouts and a pair of walks in 3 2/3 frames.
Lackey was charged in defeat for five hits and two runs, despite fanning eight with one walk.