McCoy started at second base in Saturday's game against the Tampa Bay Rays.
Nix started at second in Friday's 6-4, 11-inning win over the Rays but came out of the game in the second inning after Sean Rodriguez slid into him breaking up a double play. Nix was already nursing a sore knee before the injury to his shin.
In 17 games, Nix is batting .244 with two homers and five RBIs, while McCoy is batting .364 with no RBIs in seven games.
Third baseman Edwin Encarnacion was a late scratch from Saturday's starting lineup because of a sore left wrist.