James Harden suffered a concussion as a result of the elbow thrown by Metta World Peace during the first half of Sunday's game against the Lakers. According to Darnell Mayberry, he is now listed as day-to-day after preliminary testing.

Update on James Harden | NewsOK

Harden will likely miss the remaining two games as he undertakes the NBA's new concussion policy. Says Mayberry:

The NBA’s new concussion policy, which was instituted at the start of training camp this season, mandates that players diagnosed with concussions must undergo neurological testing and pass a series of exertion protocols that include riding a stationary bike, jogging and individual basketball skills.

The NBA's new policy is tailored to the specifics of each individual player, so return to action is judged on a case-by-base basis. Earlier this season, ESPN reported the general progression of the testing:

*During the preseason every player in the NBA undergoes baseline neurological testing.

*If a player is diagnosed with a concussion, he's no longer allowed to play until cleared in consultation with the NBA's director of the concussion program, Dr. Jeffrey Kutcher, an associate professor of neurology at the University of Michigan.

*To gain clearance, a player must return to his symptom free neurological baseline, then complete a series of exertion tests, each growing in difficulty (from a stationary bike to jogging, to agility and individual basketball drills) remaining free of symptoms after each test.

*There is no set amount of time that must pass between each exertion exercise. Testing is situation specific, and relies on the medical judgment of the doctors and other medical personnel involved.