James Harden (concussion) is 'day-to-day' after Metta World Peace elbow

James Harden is now day-to-day after taking a Metta World Peace elbow to the head. (Getty Images)

Metta World Peace knocked James Harden out of a Sunday afternoon game at Staples Center with a vicious elbow to the head, and now the Oklahoma City Thunder guard is listed as "day-to-day" after being diagnosed with a concussion.

The Thunder made the announcement on Monday.

James Harden continued to undergo tests today in Oklahoma City that followed NBA protocol for the concussion he suffered in yesterday's contest against the Los Angeles Lakers.

Harden participated in a series of limited activities per NBA guidelines, but has additional steps that must be taken under the league-mandated concussion policy before he can make his return to the court.

He will be re-evaluated tomorrow and is currently listed as day-to-day.

On Sunday, The Oklahoman reported that Harden was diagnosed with a concussion after taking the swinging left elbow to his head during the second quarter of a 114-106 double overtime loss to the Los Angeles LakersLakers.

The Thunder conclude their 2011-2012 regular season schedule by hosting the Sacramento Kings on Tuesday and the Denver Nuggets on Thursday. The Thunder are currently the No. 2 seed in the Western Conference, with a record of 46-18, and would face the Dallas Mavericks if the playoffs began on Monday.

Harden is subject to the NBA's new concussion policy, which mandates that Dr. Jeffrey Kutcher, a professor of neurology at the University of Michigan and the Director of the NBA's Concussion Program, must independently clear Harden before he can return to the court.

Harden was evaluated multiple times during Sunday's game and did not return to action. Harden was knocked from the game after posting 14 points, 3 assists and 1 steal on 5-for-7 shooting in 13 minutes.

After the game, World Peace apologized for his actions and said that the foul was "unintentional."

Here's video of James Harden receiving a concussion from Metta World Peace's swinging left elbow.