Ibaka suffered a contusion on the left side of his chest in the third quarter of Friday night's 116-101 victory over the Los Angeles Lakers at Staples Center and did not return.
In addition, starting guard Thabo Sefolosha (sore neck) is a game-time decision to whether he will play against the Blazers.
Nick Collison will start in Ibaka's place. If Sefolosha cannot play, Kevin Martin will start at the shooting guard position. While the Thunder should be able to whether the storm offensively, the injury situation suddenly makes their bench extremely weak.
Look for Hasheem Thabeet to get extended minutes tonight, along with DeAndre Liggins, who has slowly begun to crack the rotation. Also, tonight could be a high-scoring affair, so Jeremy Lamb might get called into duty.