Giants first baseman Brandon Belt is not in the starting lineup for Wednesday's matchup with the Diamondbacks.
Belt left Tuesday's game with a groin injury and was scheduled to undergo an MRI Wednesday. With the first baseman sidelined, catcher Buster Posey will shift to first base and Hector Sanchez will enter the game at catcher.
The Giants will also start Matt Duffy at second base and Justin Maxwell in right field Wednesday, sending Joe Panik and Gregor Blanco to the bench.