Clippers rookieseason is over. Then again, it never really started for the star-crossed Clipper.

The Clippers announced today that the power forward experienced some "discomfort in his recently accelerated rehabilitation program" and will require knee surgery, meaning he will be out for four to six months.

The team said this afternoon that Griffin will have surgery on his knee on Jan. 20 in Los Angeles.

The No. 1 pick in the NBA draft last summer suffered a stress fracture in his left kneecap in the Clippers' final preseason game in October, and had only recently been cleared to increase his workload, late last month. The Clippers had hoped he would soon be able to practice.

The team said, in a statement: "It has been determined that the healing in his left patella area has not improved to the expected required level."

Clippers Coach Mike Dunleavy said: "Obviously it's disappointing for Blake, and for us, because of the impact we think he could have had on our team. The most important thing we've considered, obviously, is how we get him healthy for the long term."

Apparently Griffin felt discomfort when he was doing some jumping in the pool, one of the steps he needed to do before proceeding to the next level of his rehabilitation.

"He experienced some pain [in the pool], and obviously when I heard that, that wasn't good news," Dunleavy said. "But I didn't know it would turn into the point where he would quickly need knee surgery."

More to come at latimes.com/sports

-- Lisa Dillman, reporting from New Orleans

Photo: Blake Griffin in an exhibition game in October. Credit: Chris Pizzel / Associated Press