PORTLAND, Ore. -- Portland Trail Blazers center Greg Oden, the former No. 1 draft pick whose short career has been marred by injuries, will have microfracture surgery on his left knee and will not play this season.

Oden hasn't played since last December because he needed surgery to repair a fractured left patella. The Blazers say this operation, announced Wednesday night and scheduled for Friday in Vail, Colo., will repair damaged cartilage and is unrelated to the patella injury.

Oden, the first name announced in the 2007 NBA draft, missed his rookie season because of microfracture surgery on his right knee. The procedure stimulates cartilage growth.

He was having arguably the best season of his career when he broke his left kneecap during a game last December against the Houston Rockets. He was averaging 11.7 points, 8.8 rebounds and 2.4 blocks as a starter.

The 7-footer has often been compared to former Portland center Sam Bowie, who the Blazers famously selected in front of Michael Jordan in the 1984 draft.

The Blazers picked Oden instead of Kevin Durant, who went to the Oklahoma City franchise and has blossomed into one of the NBA's best players.

Another Portland big man, Bill Walton, was selected by the Blazers with the No. 1 pick in the 1974 draft, but he was dogged by a broken nose, foot, wrist and leg over his first two seasons before helping the team to the NBA championship in 1977.

It had been expected that Oden would play this season, but at the start of fall practice he said he wasn't close. When asked if he may return by Christmas, Oden shrugged his shoulders and threw up his hands.

The former Ohio State star has played just 82 games over parts of two seasons, averaging 9.4 points and 7.3 rebounds.

The Blazers announced last month they would not offer Oden a contract extension. He was the first No. 1 pick since Kwame Brown not to get one at the end of his rookie contract.

Oden will be a restricted free agent next summer and the Blazers will be able to match any offers for him.

In Oden's absence, the Blazers have largely relied on center Joel Przybilla, but Przybilla was also injured last December and required knee surgery. The Blazers have since started veteran forward Marcus Camby in the middle.

The Blazers were further hurt at the position at the start of this season when Jeff Pendergraph, who was backing up Camby, injured his knee and required season-ending surgery.

 Przybilla has already returned to practice and has said he expects to be back by Thanksgiving.