“It’s hard to put into words the heartbreak for everyone involved, but especially for Greg. He’s a young man who has experienced a great number of physical challenges in his playing career and today is yet another significant setback for him,” Trail Blazers president Larry Miller said in a prepared statement.

“We have a lot of empathy for Greg and his family during this difficult time.”

Oden, who has not played in an NBA game since Dec. 5, 2009, has appeared in 82 career games for the Blazers, averaging 9.4 points and 7.3 rebounds.

It was expected that he might be able to play this season, but a checkup before the start of training camp in December reportedly revealed concerns about a non-weight-bearing ligament in the left knee, further setting back his rehabilitation.