Tyler Wade, ranked by MLBPipeline.com as the Yankees' No. 10 prospect, will be called up from Triple-A Scranton/Wilkes-Barre to take Castro's spot on the 25-man roster.
Castro tweaked the hamstring on Wednesday against the Twins while fielding a slow roller at second base. Girardi said he didn't know the severity, but there was bruising on the back of his leg after Friday's game, which indicated he needed more time to rest and recover.
"He argued he was fine and he could play, and he's still arguing he's fine and he can play," Girardi said.