Blake Griffin suffered a left knee injury during Monday's win by the Clippers over the Lakers.
"It didn't look good," Doc Rivers said. "But we'll just have to wait and see."
Griffin left the locker room without speaking to reporters.
"I knew immediately, I thought," Doc Rivers said. "But then Blake said he was OK. I just saw his leg go in, and then when they switched on back-to-back plays, he couldn't move so we had to get him out of the game."
According to Broderick Turner of the Los Angeles Times, the early indications are Griffin suffered a sprained MCL and will be out for an extended period.