Yastrzemski (hamstring) was placed on the 10-day injured list by the Giants on Friday, Alex Pavlovic of NBC Sports Bay Area reports.
Yastrzemski was reportedly feeling better Thursday but still wasn't 100 percent when he tested his hamstring before Friday's game versus the Diamondbacks. Isan Diaz was recalled from Triple-A in a corresponding move. Blake Sabol will likely get the majority of the available reps in the outfield with Yastrzemski out of action.