After getting an elbow to the head from Metta World Peace on Sunday, James Harden might be forced to miss some of the action in the Oklahoma City Thunder's first round playoff series, which begins next weekend. He'll need to pass several concussion tests to be able to get back on the court, explains Darnell Mayberry of The Oklahoman.

Under the NBA's newly instituted concussion policy, Harden can return to the court only after passing a rigorous evaluation process that could take several days.

Once he's considered free of concussion symptoms, Harden must make it through increasing stages of exertion — from riding a stationary bike, to jogging, to agility work, to individual basketball skills — while ensuring the symptoms don't return after each stage.

If he passes those tests, the Thunder would then have to consult with Dr. Jeffrey Kutcher, the director of the NBA's concussion program, to figure out when he can return.

For more on Harden and the Thunder, head over to Welcome to Loud City. Be sure to stick with SB Nation NBA for the latest on the fallout from Sunday's incident as it becomes available.