"He had a couple of plays that really don't come up a lot," Bochy said, adding that he still intends to use Sanchez and fellow catcher Buster Posey as occasional alternatives to Michael Morse, who's expected to receive most of the playing time at first while Belt's fractured left thumb heals.
Sanchez remained prepared for whatever comes his way.
"You never know what can happen," he said.
Bochy appreciated Sanchez's eagerness.
"He's not nervous," Bochy said, describing Sanchez's upbeat attitude about playing first.
Chris Haft is a reporter for MLB.com. Read his blog, Haft-Baked Ideas, and follow him on Twitter at @sfgiantsbeat. This story was not subject to the approval of Major League Baseball or its clubs.