The kick came in the third quarter of Houston's 105-103 overtime win on Sunday, after James tried grabbing the ball from Harden as Harden was falling backward. Once on the ground, Harden's left foot appeared to kick James.
After the game, multiple Cavaliers players were upset that Harden was not ejected for the kick, which drew a flagrant foul call. J.R. Smith called it a "dirty play" and James Jones said it "was an intentional groin kick."
Harden said afterward that the kick was not intentional and was "just a reaction."
The suspension will cause Harden to miss his first game of the season.
The Rockets play the Hawks in Atlanta on Tuesday.
- Molly Geary