Kyle Drabek was forced to leave Wednesday afternoon's 6-2 loss to the Nationals in the fifth inning because of a right elbow injury.

Drabek felt a pop in the elbow while throwing his 85th pitch of the game, and he immediately called for trainer Hap Hudson and manager John Farrell.

The Toronto right-hander passed a series of tests in the clubhouse, but he will need to undergo further evaluations on Wednesday night before a timetable for his return can be established.

"I threw the ball and I kind of felt a little popping sensation in the back of my elbow," Drabek said. "I don't know how fast [the pitch] was, but I knew the velocity was down. Just for a precaution, [it was] probably smart to take me out."