Ramirez felt tightness in his right side during a pregame session in the batting cage Friday night, but tried to play through the pain as the Dodgers opened a three-game series with the Brewers with a 9-3 loss.
Ramirez batted fourth in the starting lineup and walked in the first inning. After talking with Dodgers manager Don Mattingly in the dugout, Ramirez was removed as a precaution in the bottom half.
Mattingly said it sounded like an "oblique-type" injury. The tests would indicate whether there was swelling or bleeding.
Ramirez is batting .277 with 12 home runs and 58 RBIs in 100 games this season.