Recurrence of back issue sidelines Posey

ST. LOUIS -- Back problems struck Buster Posey for the second week in a row, preventing the Giants catcher from starting Thursday night's series opener against the St. Louis Cardinals.

Nerve irritation in Posey's lower back forced him to miss games against the Colorado Rockies on May 20 and 21. He insisted the flight to St. Louis did not aggravate his discomfort.

"It's nothing crazy," Posey said. "It's just off a little bit."

He said he felt "pretty back to normal" between the time his previous episode subsided and Thursday.

Posey, who's in a 3-for-34 skid that has lowered his batting average to .254, declared himself available to pinch-hit.

Giants manager Bruce Bochy indicated that he didn't consider Posey's injury serious and rejected the notion that this could be a recurring health issue. But Bochy wants to guarantee that Posey's ailment doesn't become chronic.

"We'd like to get this thing taken care of," Bochy said.

Hector Sanchez replaced Posey, starting his 18th game behind the plate.