Cueto was diagnosed with a mild flexor strain Tuesday, Alex Pavlovic of NBC Sports Bay Area reports. He will be reevaluated in a week.
Cueto was nearing his return to the Giants' rotation before suffering a setback in Monday's rehab start with High-A San Jose. The veteran hurler was removed with forearm tightness, but after further examination, he was officially diagnosed with a mild flexor strain. Cueto suffered a flexor strain in 2015 with the Reds and was only sidelined for one game, but fellow Giants pitcher Matt Cain missed the first two months of the 2017 season with a similar injury. The Giants are confident that Cueto will be able to return to the rotation later this season.