Blake Griffin's injury-ravaged rookie season with the Los Angeles Clippers ended on Wednesday when the power forward was ruled out for another four months to have surgery.

The No 1 overall pick in the NBA Draft, Griffin is yet to play a regular-season game for the Clippers, having fractured his left kneecap in their final preseason game on Oct 23.

"It has been determined that the healing in his left patella area has not improved to the expected required level," the Clippers said on their official website.

"Griffin will undergo a surgical procedure in the near future, with a recovery prognosis of four to six months. Further details will be made available as events develop."

Griffin had been sidelined since suffering a non-displaced stress fracture of his left patella against the New Orleans Hornets.

A medical examination in Los Angeles on Tuesday revealed the 6ft-10in (2.08), 250 pounds (113 kg) forward required surgery.

The success-starved Clippers have made the playoffs just once in the past 12 years and had viewed Griffin as the cornerstone of their rebuilding effort after acquiring him as the top overall NBA draft pick in June.

An Oklahoma City native, Griffin averaged 22.7 points and 14.4 rebounds in his final season for the University of Oklahoma and was the consensus collegiate Player of the Year.