NEW YORK -- A's starter Jesse Hahn returned to Oakland on Thursday to undergo an MRI exam on his right elbow, and he's not expected to make his scheduled on Saturday start in Cleveland, MLB.com has learned. The A's have not confirmed the news.

Hahn was to pitch against the Indians on nine days' rest after experiencing tightness in his pitching elbow, but the A's weren't overly encouraged by his Wednesday bullpen session in New York, instead opting to have him checked out as a precautionary measure.

Hahn, who is 6-6 with a 3.35 ERA in 16 starts, underwent Tommy John surgery in 2010 and said Wednesday this is the first time he's had any elbow issues since the operation.

Right-hander Chris Bassitt, who recently allowed three runs over 10 2/3 innings spanning two spot starts for Sonny Gray, is expected to be recalled from Triple-A Nashville and pitch in place of Hahn on Saturday.