"He's a strong kid," said general manager Kevin Pritchard, visibly shaken by the latest injury to befall the 7-foot center. "He's going to bounce back from this."
Oden dropped to the floor clutching his left knee and grimacing after colliding with a driving Aaron Brooks midway through the first quarter.
Oden was almost immediately surrounded by trainers and physicians. The crowd at the Rose Garden stood and chanted "Oden! Oden!"
The game was stopped for some 7 minutes. Finally, Oden was gently moved to a stretcher and wheeled from the court. He underwent an MRI shortly thereafter.
The Blazers said Oden will need surgery. A timetable for his return was not immediately set.
"I'm obviously disappointed having worked so hard to get to where I was. This is a setback but I'll be back. It's in God's hands now," Oden said in a statement released by the team. "I want to thank the fans, my teammates and everyone in the Blazers family for all of their good thoughts."
Oden, the No. 1 pick in the 2007 NBA draft out of Ohio State, has been plagued by injures his entire NBA career.
The 7-footer missed rookie season after undergoing microfracture surgery on his right knee. Last season, Oden sat out six games after injuring his right foot in the season opener against the Lakers, then missed 14 games after the All-Star break with a bone chip in his left knee. He finished the season averaging 8.9 points and 7 rebounds.
Oden lost weight during the offseason and was averaging 11.7 points and 8.8 rebounds this season as a starter.
"I thought he was the most consistent player this short season," coach Nate McMillan said. "For him to go through this -- it's just unfortunate for him because he worked so hard."
Blazers guard Brandon Roy said Oden spoke to the team at halftime, after he had learned of the diagnosis.
"He told us to keep fighting," Roy said. "He feels like he's letting us down."
Portland went on to edge the Rockets 90-89, ending a three-game losing streak. But Oden's injury felt like a "punch in the gut," Pritchard said.
The Blazers have been beset by injuries. Starting forward Nicolas Batum needed shoulder surgery just before the opener. Fellow forward Travis Outlaw fractured his foot in mid-November and required surgery.
Forward Rudy Fernandez was out of Saturday night's game with sciatic pain and set to undergo an MRI. It was uncertain if he would be with the team on an upcoming four-game trip starting with the Knicks on Monday night.
Even McMillan was set to undergo surgery Monday after rupturing his right Achilles' tendon during practice.
The coach was participating in practice because the team is so short-handed. He will miss the team's upcoming road trip, replaced by assistant coach Dean Demopoulos.