Ike Davis understands why he has lost playing time to Pedro Alvarez.

“Petey hit something like five home runs in two days,” Davis said with a smile. “He deserves to play. You can't really argue with that.”

In a tense eighth inning Tuesday, Davis made a case that maybe he has earned another look. He smacked a pinch-hit, three-run, homer that lifted the Pirates to a 5-2 victory over the St. Louis Cardinals.

Alvarez and Andrew McCutchen left the game early with injuries.

McCutchen departed in the sixth inning after he aggravated the left rib injury that put him on the disabled list from Aug. 4-19.

“I'm not 100 percent,” McCutchen said. “I don't want to push it and make it worse. I'm not fully healed, so there are going to be days when I'm a little more sore. Today, I was more sore. It didn't help when I jumped into that wall.”

With two outs in the third inning, Matt Carpenter hit a fly ball to deep center field. McCutchen caught it, then slammed his back into the outfield wall. McCutchen doubled over for a long moment, then slowly jogged to the dugout.

McCutchen said he expects to play Wednesday when the Pirates and Cardinals wrap up their three-game series at PNC Park.

Alvarez started at first base and was replaced by Gaby Sanchez to start the top of the seventh. Alvarez left with what manager Clint Hurdle described as a sprain between two of Alvarez's toes.

If Alvarez needs down time, Davis could get more at-bats. Davis has not started a game since Aug. 19, but he doesn't seem fazed by his backup status.