Rolen and team officials preached patience, with all agreeing that little will be known for sure until Wednesday.
"I think we'll wait and see how I recover tomorrow," Rolen said. "They told me I subluxed it. I heard it pop when I hit it. For lack of a better term, I guess it's a sprain. Tomorrow -- they said 24, 48 hours -- we'll see how it reacts and go from there."
With runners on first and second in the fifth inning, Rolen hit a comebacker to Los Angeles pitcher Scott Erickson. The throw from Erickson to first baseman Hee-Seop Choi forced Choi into an awkward position and directly in Rolen's path. Rolen put up his arms to soften the blow, but the collision threw his shoulder somewhat out of joint -- a condition known as subluxation.
"I'm not feeling too good right now," Rolen said. "I've got ice, that numbed it up a little bit. They gave me anti-inflammatories, so hopefully that will take some of the swelling out of it. But I can't say I feel real good."
A collision with Arizona's Alex Cintron knocked Rolen out of the 2002 postseason, also with a left shoulder injury. That injury was called a "moderate shoulder sprain." However, the 2002 injury occurred in a different area -- the SC (sternoclavicular) joint, where the collarbone meets the breastbone. This is in the main shoulder socket.
"Tonight is not important," said Cardinals head athletic trainer Barry Weinberg. "It's over. What happens tomorrow is important. We'll see how he feels Wednesday, how much mobility and pain he has."
Choi was also a bit shaken up in the collision. He was tended to by the Dodgers' medical staff, but he remained in the game. Abraham Nunez replaced Rolen at third base.
Rolen, a six-time Gold Glover, was already nursing a sore neck, which kept him out of action for two games in Cincinnati last week. However, he was in good enough shape to rip a two-run homer in the fourth inning on Tuesday, igniting a Cardinals comeback from a 3-0 deficit. Rolen is batting .257 with five home runs and 20 RBIs in 2005.
If he has to go on the disabled list, Nunez and John Mabry would likely share time at third base. Nunez is the superior defensive player, but Mabry is a much more dangerous hitter. Rolen has been on the disabled list once in his career: in 2000, for an ankle sprain.
Matthew Leach is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.