Manager Manny Acta said Friday the team is awaiting results of an MRI exam on the veteran designated hitter, who did not take batting practice.
Acta added that Hafner, hitting .342 with four homers and 11 RBIs in 21 games, was available. He had been scratched from the lineup Thursday night.
Hafner's hot start has been one of the keys to the Indians' first-place standing in the AL Central. Cleveland was putting a 10-game home winning streak on the line in the opener of a three-game series against the Detroit Tigers.