Ramirez suffered a bruised right quad in Sunday's matchup against the Nationals, Zach Buchanan of the Cincinnati Enquirer reports.
Ramirez sustained the injury after getting hit with a comebacker in the sixth inning, and had to be replaced by Josh Smith shortly afterwards. Given it's only a bruise, it shouldn't cause the relieve a significant absence, though it wouldn't be surprising to see him rested for a day or two.