Clevinger's back strain is significant enough that he won't be able to pick up a baseball for 6-to-8 weeks, Ryan Lewis of the Akron Beacon Journal reports.
Clevinger suffered the injury in Sunday's start against the Blue Jays and initially expected to make his next start, but he'll now be out for quite some time. He'll need to get back into game shape following such a long absence, which would likely push his return into early or mid-June. The Indians haven't announced his replacement in the rotation.