Rolen was beaned on the left side of the head by a pitch from Jason Marquis on Sunday. He sat out a 4-2 loss to Chicago on Monday night due to dizziness and a headache.
He felt better on Tuesday, but was out of the lineup against the Cubs as a precaution. Rolen planned to work out and take batting practice.
The Reds got Rolen from Toronto on Friday in a four-player trade.