CHICAGO -- Atlanta Braves second baseman Marcus Giles left Friday's game against the Chicago Cubs with a mild concussion after a violent collision with Mark Prior while trying to field a grounder.

	Mark Prior grabs his shoulder after a collision with the Braves' Marcus Giles, but he stayed in the game.

Giles was taken to a hospital for further tests and was released shortly after the Braves won 9-5.

With two outs in the second inning, Prior was running from first on a grounder hit to Giles when the two slammed into each other on the basepath. Prior was called out for interference.

Prior's left knee appeared to hit Giles flush in the face as the Cubs pitcher toppled over Giles, falling on his right shoulder.

After laying on the ground for a couple minutes, a wobbly Giles walked off the field and was replaced by Mark DeRosa.

"It was definitely scary. I don't think Marcus is in Prior's weight class,'' Atlanta pitcher Mike Hampton said. "I could tell Marcus was knocked out by the way his body was stiff.''

Prior grabbed his shoulder after the collision, wincing with pain, but eventually walked off the field to cheers. Prior stayed in the game, and struck out two of the next three batters he faced after the collision before leaving the game in the fifth.

Prior and Giles were picked for the All-Star team, a first for both players.

Prior, who said his shoulder stiffened up on him in the fourth inning, didn't think the injury was too serious.

"I got it checked out. I don't feel anything physically wrong. I don't think there's anything structurally wrong,'' Prior said. "I think at most it's probably going to be sore for a couple days.''