Manager Tony La Russa said LaRue suffered a mild concussion and had sore ribs from the first-inning altercation the previous night. LaRue is one of the players kicked by Reds starter Johnny Cueto after he got pinned against the backstop screen.
"His ribs are real sore," La Russa said, before the final game of the series on Wednesday. "He'll get X-rays when we get back to St. Louis. So we'll be very careful with him."
The Cardinals called up Steven Hill from Double-A Springfield. The 25-year-old catcher will be making his major league debut. St. Louis also put right-hander Jeff Suppan on the 15-day disabled list with a sore groin. Suppan felt discomfort while working out Monday, and the Cardinals want to be cautious.
La Russa expects Major League Baseball to take disciplinary action against the Reds.
"I just believe it's something significant," La Russa said. "I don't know what it's going to turn out to be."
The brawl centered on Reds second baseman Brandon Phillips, who said at the start of the series that he hates the Cardinals. He also called them complainers, using demeaning language that riled St. Louis.
When he came to bat in the first inning Tuesday night, he tapped catcher Yadier Molina's shin guard with his bat in a sign of friendship. Molina mentioned Phillips' comments and told him not to touch him. It quickly escalated into shouting, and both benches and bullpens emptied.
Cardinals pitcher Chris Carpenter ended up pinned against the backstop screen. Cueto also was pinned against the backstop nearby and kicked players around him. He later said he was afraid and trying to defend himself.
Major League Baseball will watch video of the fight and get a report from the umpiring crew before deciding any punishment. Reds manager Dusty Baker said there was more to it than the video might show.
"I just hope the guys up there realize the tension, the pressure, the background," Baker said. "Also, you can't just go on the video because you don't know what was said. ... That thing was over until some people started talking."
Baker said it was premature to think about possible discipline.
"It's like asking when you're going to jail and you haven't gone to court yet," Baker said.
The Cardinals won the game 8-4, moving percentage points ahead of the Reds in first place in the NL Central. The standings board at Great American Ball Park refused to acknowledge the change of order on Wednesday, keeping Cincinnati listed above St. Louis. The teams were tied in the games-behind column, though St. Louis had the better winning percentage.
The organist played the theme from "Rocky" when a fan threw a ceremonial pregame pitch. The Reds' mascots acted like boxers, pretending to throw punches on the side.