"Hopefully today with treatment it can better," Molina said on Wednesday afternoon. "Tomorrow, we'll see where we are."
Molina said he felt the tightness in his back during pregame work in the bullpen on Tuesday, but chose to play regardless. Molina was 0-for-3 with a walk and was not running well, prompting manager Mike Matheny to sub in backup Tony Cruz to catch the ninth inning of an 8-2 win.
Molina said he'd been dealing with soreness in his left side for nearly two weeks after he'd aggravated the area stealing third in a game against Milwaukee on Aug. 3. That injury was not serious, but Molina believes his back may have tightened because he was attempting to not put as much pressure on his side.
"He's pushing right now because he knows everybody needs to push," Matheny said. "But he's going to have to sit for at least today, and we'll have to see how he feels tomorrow."
Cruz got the start on Wednesday, hitting seventh in the Cardinals lineup. He is batting .226 with eight RBIs in 32 games (19 starts) this season.
Matheny said Molina could be available to pinch-hit or catch a few innings on Wednesday if needed. While Molina admitted his tight back limits him in his movement, swinging and running, he said he'd gladly step up if called upon.
"I put some heat on it, and let's go," Molina said.