The Astros right-hander left Monday's start against the Pirates in the third inning with what was being called a right knee sprain. Moehler had an MRI on Tuesday morning in Pittsburgh with the hopes that nothing serious would be found with the knee, which had been bothering him on and off for the past few weeks.
The diagnosis: a mild sprain of the medial collateral ligament. The status: day-to-day.
Moehler said on Monday that it was particularly bothersome because it was his push-off leg and it was greatly hampering his delivery to the plate. It likely contributed to Moehler's 0-2, 27.00 ERA start to the 2009 season.
There was no word about whether Moehler would be able to make his next scheduled start on Sunday, with the plan to see how he felt on Wednesday before determining if a move would have to be made to replace him in the rotation.
Jonathan Mayo is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.