Giants manager Bruce Bochy said Sanchez's ability to add another dependable bat in the lineup as well as effectively handle the pitching staff has brought an appreciated flexibility to the position.
"It's a rare quality when you have a young backup like we have where our veteran pitchers have a lot of confidence in him," Bochy said.
The switch-hitting Sanchez entered Sunday batting .284 in 74 plate appearances with 17 RBIs this season.
Posey and Sanchez have combined to handle a Giants starting pitching staff that had a 3.40 ERA on the season, good for third best in the National League.
"With the young catchers [we have] and the talent that these guys have and the things that they can do," Bochy said. "Most importantly, they have the ability to handle this staff, which is not an easy staff to handle."