Victor Martinez's balky left knee, sprained on a play at the plate two weeks ago, is improving, but there is no timetable for when he might be available to catch, head athletic trainer Kevin Rand said.

That means the Tigers will go with Alex Avila exclusively behind the plate, and Don Kelly as his emergency backup. Omir Santos with Triple-A Toledo could be recalled if needed.

"If we did run into an emergency situation, we could get through one game and we'd have a catcher here the next day," Tigers manager Jim Leyland said.

Rand said with an injury like Martinez's knee sprain, when the player is not 100 percent but able to play, "you find the best way to do things to improve him while, at the same time, he's out there functioning."