Buster Posey began Thursday night's game in St. Louis on the bench because of the same back problem that cost him two games last week.
Posey missed games on May 20-21 against the Rockies due to nerve irritation in his back. He has gone 3-for-25 with six strikeouts in the seven games between the two flare-ups.
His struggles at the plate began before he sat out the pair of games, and he's now mired in a 5-for-45 slump that has dropped his batting average from .306 on May 11 to .254 entering play on Thursday.
Giants manager Bruce Bochy told the media before Thursday's game tonight he didn't consider Posey's back troubles major, but instead something the team needs to get taken care of so Posey can be himself on a nightly basis. Harold Sanchez started in place of Posey.