"You get sick to your stomach a little bit, because you fear the worst," manager Tony La Russa said. "When you're talking neck, spinal injury and stuff. It's very scary and we'll see. Hopefully we're OK."
After he was carted off the field, Molina was transported to a local hospital where he could be evaluated for back and neck pain.
According to the Cardinals' medical staff, Molina sustained a mild concussion and will remain hospitalized overnight as a precautionary measure.
With runners at the corners, Jimmy Rollins hit a sharp ground ball to Chris Duncan at first base. Duncan gunned the ball home to Molina, who barely applied the tag to Bruntlett before he took a shot to the head.
On the replay, it appeared Bruntlett's elbow hit Molina in the head and the Cardinals' catcher fell head-first to the ground, holding onto the ball for the out.
"His back was to the runner," said backup catcher Jason LaRue. "You don't see the runner, you don't know when you're going to get hit. For him to get the tag in ... he did an unbelievable job."
For several minutes, Molina lay on the ground motionless while Cardinals doctor Wendell Becton treated Molina. La Russa said Molina remained consciousness the entire time, but was told to stay still.
"He's a tough [guy]," La Russa said.
Almost all of the position players ran to the plate following the hit to check on their teammate.
"Just seeing that happen right there, that even gets my adrenaline going more," said reliever Ryan Franklin, who was pitching the ninth, "because that's one of my brothers down there, just got knocked down and hurt. It kind of builds more fire inside of me.
"How he held onto the ball, I don't know."
Following the game, the Cardinals sounded optimistic that Molina will be able to return. With a day off on Monday, the organization has an extra day to wait to make a move, if one is needed.
Besides LaRue, the catcher position is sparse without Molina. Bryan Anderson would be the likely callup from Triple-A Memphis if Molina were to go on the disabled list.