James also sat out Tuesday's OT win against the Spurs due to the injury.
Anthony Davis, who went down with a right knee injury late in the fourth quarter of Tuesday's win, did play against the Thunder, scoring 30 points.
James suffered the injury in Sunday's win against the Memphis Grizzlies when Desmond Bane fell into James' right leg after scoring a layup, causing James to go to the floor. He did not test the ankle out on the court Tuesday and sat out against the Spurs while Malik Monk started in his place, scoring 17 points.
James missed 26 games last season with a high right ankle sprain, but coach Frank Vogel on Tuesday said it was unrelated to that injury.
"Same ankle. Different spot. Different injury," Vogel said.
Davis, who stayed in the game for the final 32.2 seconds of regulation after injuring the knee, said he received ice and treatment on the knee in the locker room but didn't undergo further evaluation Tuesday night.
ESPN's Dave McMenamin contributed to this report.