Molina described his knee as feeling "about the same" on Saturday as it did when he left the ballpark on Friday night.
"I'm a little sore, a little tight," he added. "Hopefully with treatment, I can get back on track for tomorrow."
That treatment included ice, massage therapy and electrotherapy on Saturday. While he did not hit during the team's batting practice, Molina did take the field and played some light catch. Neither he, nor Matheny, ruled him entirely out of commission on Saturday, leaving open the possibility of using Molina to pinch-hit.
"He felt better than what he thought he was going to feel, but we pretty much made up our mind last night before we left the clubhouse that we'd give him another day here," Matheny said. "It wasn't as swollen. He's still sore. It's just getting down in the catcher's squat that is giving him trouble more than anything else."
If Molina does not show much improvement over the next 24 hours, Matheny said the organization will reevaluate its roster situation and potentially call up an additional catcher as insurance. On Saturday, that emergency catcher will be infielder Pete Kozma.
Kozma did a little work behind the plate this spring in preparation for such a spot, and he caught a bullpen session on Saturday afternoon to stay ready. As long as Tony Cruz is healthy, however, he'll take the catching workload until Molina's return.
"If we get him in there, we're in a firestorm," Matheny said of Kozma. "I'm not worried about him blocking. I'm worried about him not getting hurt. You'll see he'll have a thumb guard on and everything is about getting through it more so than trying to shine. Now, I'm sure he'll want to throw somebody out and block balls and all that, but we're just trying to get through it. If we got to that point, we'd obviously need to get somebody else here in a hurry. It's just a matter of getting through the game."
Jenifer Langosch is a reporter for MLB.com. Read her blog, By Gosh, It's Langosch, follow her on Twitter @LangoschMLB and like her Facebook page Jenifer Langosch for Cardinals.com This story was not subject to the approval of Major League Baseball or its clubs.