Blake Griffin of the Los Angeles Clippers faces a recovery time of up to six months after his injury setback. ((Chris Pizzello/Associated Press))

Blake Griffin of the Los Angeles Clippers, the top pick in the 2009 NBA draft, will undergo season-ending surgery, the club announced on Wednesday.

Griffin, 20, injured his left kneecap in the team's last pre-season game in October and has not played in the regular season. It was hoped at the time of the injury that he would return in January or February.

"As a result of that examination, it has been determined that the healing in his left patella area has not improved to the expected required level," the Clippers said in a statement. "Griffin will undergo a surgical procedure in the near future, with a recovery prognosis of four to six months."

The six-foot-10 power forward was selected first overall after being named the Naismith Award winner as the top U.S. college player while at Oklahoma.

Los Angeles is 17-19, putting them in 12th place in the Western Conference. The Clippers made the playoffs in 2005-06, the franchise's only post-season berth in the last 12 years.