Molina had not appeared in a game since March 24 because of a strained right oblique muscle. He took batting practice on Saturday and worked out again on Sunday, and following his Sunday work, he was expected to be in the Opening Day lineup. But it was not a certainty until he came to the park on Monday, when he was officially cleared.
"Good workout the last two days, so he's ready to go," manager Tony La Russa said.
La Russa did not commit to a schedule for Molina's playing time. Molina started the Cardinals' first seven games last season, and typically, he has been among the leaders in playing time for National League catchers.
"[We'll] see how he feels," La Russa said. "We've got a day off tomorrow. He'll catch [Adam Wainwright on Wednesday]. Then we've got a day game, we'll see."
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.