For the third time in his four-year career, former Buckeye and NBA No. 1 overall draft pick Greg Oden has suffered a season-ending injury.

Oden missed the start of the season while rehabbing a fractured patella in his left knee, an injury that ended his 2009-10 campaign after 21 games. It was the same knee that required microfracture surgery Friday.

The Portland Trail Blazers officially addressed the injury in a press conference Wednesday. Team trainer Jay Jensen said that even though the injuries occurred in the same knee, they were not related.

“Greg’s patella fracture and his chondral injury that he has are not related although they’re in the same knee,” Jensen said. “They are two totally separate situations.”

Oden missed his entire rookie season after having microfracture surgery on his right knee. Jensen said that in both cases, doctors didn’t know how the injuries occurred.

“It’s the same procedure. It’s the same part of the bone that was damaged in his right knee,” Jensen said.

Rose Backs, a physician assistant and assistant clinical professor in the Department of Orthopedics at Ohio State, said microfracture surgery is a technique used when a piece of cartilage breaks off in the knee and leaves a “pothole” where the bone is exposed.

“This microfracture technique involves a series of holes that are either picked or drilled into the defect, or the pothole per se,” Backs said. “There’s a little blood clot that forms in that pothole, and what happens is scar cartilage grows over that. So in essence, it patches the pothole and the cartilage.”

Backs said it could develop on its own.

“There’s a number of things that we see commonly, and most commonly is probably the late effects of a previous injury, or even just spontaneously,” Backs said.

Blazers coach Nate McMillan said Oden was devastated by the news that he would not be able to play this season.

“Being so close to getting back on the floor, just all of a sudden this situation comes up and it’s like, ‘Here we go again’ for him,” McMillan said. “As I told him, he has to stay positive, and he has to keep believing. He’ll have an opportunity to continue to work to get back on the floor.”

Oden has played in 82 out of a possible 260 games and will miss the 68 games remaining on the Blazers schedule this season.

Kevin Durant, the Oklahoma City Thunder forward who was drafted immediately after Oden, is leading the NBA in scoring. He won the league scoring title last season.

Oden will be a restricted free agent in the offseason. Team president Larry Miller said that Oden remains a part of the team’s long-term plans. The Oregonian reported that Miller foresees the team making an $8.8 million qualifying offer this summer, hoping to keep him in town for at least another season.

“We will see where (rehabilitation) things are at that level … I don’t feel like I’m ready to give up on Greg Oden,” Miller said. “I don’t think anybody in our organization is ready.”

The Blazers franchise shooting guard Brandon Roy is also struggling with knee injuries.

Jensen said that Oden practically had his own room in the Jensen household, and the trainer was noticeably shaken by the news at the press conference.

“This is a really tough day, for us to have to sit here and talk about someone like Greg who doesn’t deserve what’s going on because he’s worked his tail off to get to where he’s at to get ready to play basketball,” Jensen said. “So it’s not easy for me to sit here and talk about someone that I care deeply about.”

Jensen said he felt like someone close to him had just died when he noticed the defect on an X-ray.

He attempted to describe the injury in a way that everyone could understand.

“For lack of a better term, it’s like hitting a nine iron and taking a divot out of the grass,” Jensen said. “It’s a hole in that part of the cartilage.”

Oden declined to comment for this story.