PORTLAND, Ore. -- The Trail Blazers have offered former No. 1 draft pick Greg Oden an $8.8 million qualifying offer to stay in Portland.

The offer means the often-injured 7-foot center becomes a restricted free agent. The Blazers can match any other offer made for him.

Oden, 23, didn't play this past season after microfracture surgery on his left knee. He missed his rookie season in 2007-08 after microfracture surgery on his right knee. Two seasons ago he broke his left kneecap.

Because of his injuries, the former Ohio State star has played in only 82 games over parts of two seasons, averaging 9.4 points and 7.3 rebounds.

"We've stood behind Greg Oden every day since he became a Trail Blazer and that continues with today's announcement," Trail Blazers president Larry Miller said in a statement. "Despite the setbacks he's experienced, he continues to be resilient in working tirelessly on his rehabilitation. We're all very encouraged with not only his progress but with his commitment and determination to return to the basketball court."

The Blazers had until Thursday night to make the qualifying offer. Before he was dismissed by the team last month, former Blazers general manager Rich Cho had long hinted that the Blazers would move to keep Oden. Cho was replaced in the interim by Chad Buchanan, the Blazers' director of college scouting.

If no other teams make offers for Oden and he stays with the Blazers, he will become an unrestricted free agent for the 2012-13 season.

In the 2009-10 season, Oden was averaging 11.7 points, 8.8 rebounds and 2.4 blocks as a starter and he was playing with an authority that had previously eluded him. But he broke his right kneecap in December of that season.

It appeared he would return last season, but in November it was announced that he would require microfracture surgery on the right knee.

After the Blazers selected Oden with the top pick in the 2007 draft, choosing him over Kevin Durant, he was hailed as the future of the franchise as it emerged from the so-called Jail Blazers era.

But Oden's rookie season was postponed before it started when he had microfracture surgery on his left knee.

His numerous injuries have subjected him to endless comparisons to Sam Bowie, the frequently injured big man whom the Blazers infamously selected ahead of Michael Jordan in the 1984 draft.

Portland also extended a qualifying offer to Australian guard Patrick Mills and exercised options on forward Luke Babbitt and guard Elliot Williams.

Mills, 22, has appeared in 74 games over two seasons in Portland, averaging 5.1 points, 0.7 rebounds and 1.5 assists. But he has also been a fan favorite, often flashing the team's trademark "3-goggles" with his hands after Portland scores a 3-pointer.