John Lackey appears to have avoided a serious injury. (AP)

More MLB: Scoreboard | Standings | Probable Pitchers | Sortable Stats | Odds

Red Sox right-hander John Lackey left Saturday's start with what the team initially called a right biceps strain after he hurt himself throwing a pitch. He was sent back to Boston for an MRI on Sunday, which revealed some relatively good news, according to team president Larry Lucchino:

Lackey, 34, was in obvious pain and left the game with his arm basically dangling at his side. He missed all of 2012 due to Tommy John surgery and based on his reaction to the injury, it was easy to think he might have just re-torn the elbow ligament. A mid-biceps strain and no structural damage is pretty much the best case scenario based on his reaction.

It's unclear if or how long Lackey will be out, or who the Red Sox would use in the rotation as his replacement. Swingman Alfredo Aceves is one candidate, but the team could turn to top prospect Allen Webster or knuckleballer Steven Wright if it will be an extended stay on the DL. Aaron Harang, who the Rockies acquired in a salary dump trade this weekend and are looking to flip, could be a trade possibility.