According to Rotoworld Oct 15 - 2:17 PM
"Every day he’s done a little bit more, but they want to evaluate after he does workouts to see how he’s feeling," said head coach Billy Donovan after Monday's practice. Considering that there's yet to be any mention of Westbrook getting through full-contact, 5-on-5 work at practice, we don't anticipate him being cleared for the season-opener. For what it's worth, he's listed as "out" in the game notes.
Also for OKC.....Steven Adams is listed as questionable for the opener with lower back stiffness.