The Reds also reinstated outfielder Jay Bruce from the 15-day DL. He had arthroscopic surgery May 5 to repair a torn meniscus in his left knee.
The Reds made the moves before Wednesday's game against the Washington Nationals. Votto had already missed five games with a quadriceps strain in his left knee.
The move is retroactive to May 16.
The Reds had played a man short, expecting Votto would return quickly. Manager Bryan Price said Tuesday he was optimistic Votto would be back for a homestand that starts Friday.
Votto is hitting .257 with six home runs and 12 RBIs.