Powell suffered the injury Thursday when he scored 19 points in 34 minutes during a 112-105 loss to the Dallas Mavericks. Powell sat out Saturday's 99-97 win over the Mavericks with what the team initially called turf toe.
But the Clippers updated the injury to a fractured medial sesamoid bone in Powell's left foot on Sunday. The team said in a statement that treatment is nonsurgical "at this time" and there is no timetable for his return.
Before he was ruled out against the Mavericks on Saturday, Powell told ESPN that he was feeling better and hopeful it wasn't serious.
"It's doing a lot better," Powell said at the team's morning shootaround. "Better than it was after the game. Better than it was yesterday. Feeling better, walking better. Felt a little pain in it. All from the last game. Just going to see how it feels and go from there."
The Clippers have been hit hard by injuries this season. They entered the season without franchise star Kawhi Leonard, who has been rehabbing a torn ACL suffered in Game 4 of the Clippers' second-round series against the Utah Jazz on June 14. His return remains uncertain.
Star wing Paul George has not played since Dec. 22 because of a torn ulnar collateral ligament in his shooting elbow. George is scheduled to undergo an MRI on Feb. 24 to see how his elbow has responded to rest and to help determine whether he can still return this season.
Powell, 28, averaged 21 points in his first three games for the Clippers and was expected to help pick up the scoring load with Leonard and George out.