Bassitt (elbow) has incurred a setback while rehabbing from Tommy John surgery and was shut down from throwing, Susan Slusser of the San Francisco Chronicle reports.
Bassitt had been participating in a rehab assignment at Triple-A Nashville. Over three games with Nashville he'd thrown 13.2 innings and allowed 11 runs. The A's have yet to elaborate on the severity of Bassitt's setback. However, an early-June return is now unlikely for the 28-year-old righty.