Oklahoma City Thunder All-Star point guard Russell Westbrook won't be suiting up for tonight's NBA season-opener at Oracle Arena. According to multiple reports, Westbrook has officially been ruled out for OKC's showdown against the defending champion Golden State Warriors due to a knee injury.

Westbrook underwent arthroscopic surgery on his right knee in early September - a procedure that has been described as a "preemptive maintenance." ESPN's Royce Young notes that Westbrook experienced some stiffness in the knee during individual workouts while preparing for training camp last month.

This is the same knee that required three surgeries in a nine-month span following his collision with Patrick Beverley during the 2013 playoffs that resulted in a torn meniscus. However, Westbrook has not had any operations on the knee in four and a half years. 

The 29-year old point guard averaged a triple-double for the second consecutive season last year, posting 25.4 points, 10.3 assists and 10.1 rebounds per game. The Thunder finished fourth in the Western Conference with a 48-34 record, but we're eliminated by the Utah Jazz in the first round of the playoffs. 

After tonight's game, the Thunder will travel to Los Angeles for a Friday night matchup against the Clippers.