Backup catcher Craig Tatum took batting practice and said his knee "feels fine."
"They just wanted to get an MRI, I guess, to see if there's anything wrong," he said.
Tatum said the knee is sore, but he hasn't gotten the results of the MRI and doesn't expect them to be serious.
"I can play. I played all day Sunday with it," he said. "I don't think it'll affect me right now, but we'll see what it says. If there's anything they want to do, whatever they want to do.
"I guess since you're a catcher, your knees are pretty important."
Tatum will try to wait until the season ends if the knee requires a surgical procedure.
"I don't want to miss any more time," he said. "No matter what it was, I think I could play through it."
Update: Tatum says the MRI didn't reveal any damage.