PITTSBURGH -- A day after suffering a left shoulder, back and neck strain during a collision at home plate, Yadier Molina called Josh Harrison's hit on him a "clean play."

Molina, who said he hopes to return to the lineup on Thursday or Friday, had watched a replay of the hit by the time the Cardinals' clubhouse opened on Wednesday. Molina did not criticize Harrison for bowling him over and initiating contact with his head as Molina made a tag on the infielder to end the second inning on Tuesday in a game the Pirates won, 9-0.

"Clean play," Molina said. "Clean play. That's part of baseball. He did what he had to do, and I did what I had to do. It sucks because you don't want anybody to get hurt. This time, it was me to get hurt. But it was a clean play."

Molina will not participate in baseball activities on Wednesday, but he did report improvement less than 24 hours after taking the hit. The headaches are gone, he said, and the shoulder pain is negligible. His neck, though, remains stiff.

Molina also went through a second round of concussion tests. Like Tuesday's exams, those checked out clean.

"Not too bad, that's what I say," Molina said. "I'm OK."

He feels OK enough, in fact, that he was texting manager Mike Matheny on Wednesday asking to start on Wednesday. Matheny, well aware of the day-after effects a catcher deals with following a home-plate collision, wouldn't consider it.

"I understood why Yadi was lobbying this morning," Matheny said. "Part of it is, if I'm in there the next day, I show them that I won. He didn't say that, but that's just how we [catchers] are wired.

"I had a good conversation when he got here, and the [medical] staff laid it out. The fortunate thing is that he's really measuring out nicely with the concussion tests and they are very confident with where he is on those. That's great news. It allows us the freedom to keep moving forward without a lot of hesitation about the future."

Molina said he had not heard from Harrison since the incident, but added that the Pirates' infielder should not feel obligated to check in on Molina's health. Said Molina: "He didn't do anything wrong."

Others in the Cardinals' clubhouse were still not pleased that Harrison led into Molina's head with his left arm, noting that it seemed Harrison should have made contact elsewhere or tried to slide.

"There's always the option to slide. Always," Matheny said. "He chose not to, and within the written rules of the game, that's permissible. We get that. It is what it is."

Molina was asked if he would have initiated similar contact with a catcher had he been in Harrison's place.

"I don't know," he answered. "Right now, you don't know. You have to be in that situation and you have to react. You have to make a decision, and he decided to go after me.

"You can slide around me or you can go after me. He decided to go after me. And he was out."

Harrison, too, reviewed a replay of the collision after talking to reporters on Tuesday night, and he reiterated that he felt he "really had no other place to go."

Harrison also said that, as he was coming home, he had flashbacks to a July 4, 2011, play at the plate in which he slid feet-first into Astros catcher Carlos Corporan. On that play, Harrison was the one who took the brunt of the hit and left with a bloody nose.

"I knew I didn't want the same thing to happen again," Harrison said. "So I had to go in full-body."