The two teams will meet again Thursday in Oklahoma City, and Leonard will sit that one out as well.
Before Tuesday's loss, Clippers coach Ty Lue said Leonard has not suffered a setback with his right ACL and that the team is remaining extremely cautious with its franchise star.
Leonard is scheduled to fly back to Los Angeles on Wednesday to receive treatment on his knee. The Clippers will see how Leonard is feeling before determining his status for Sunday's game against New Orleans.
"After shootaround, [he] experienced some stiffness in his knee," Lue said before the Clippers played the Thunder. "And so we want to be cautious, make sure we're doing the right thing by him, even though he wanted to play. We just thought it wasn't smart. He can be mad at us if he wants to but just not smart right now."
Leonard was missed. Shai Gilgeous-Alexander had 33 points and Tre Mann had 25 as the Thunder rolled to their first victory of the season. The short-handed Clippers were also without Paul George (non-COVID-19 illness) and Marcus Morris Sr. (personal reasons).
Leonard, who tore his right ACL in Game 4 of the second round against Utah on June 14, 2021, played in two of the Clippers' first three games entering Tuesday, logging 21 minutes each game. He came off the bench and played in three stints to be able to finish each game. When the Clippers played a back-to-back last weekend, Leonard sat out the first game in Sacramento.
The Clippers' two-time NBA Finals MVP said it would be a process before he is back to form and that he likely would not be back in the starting lineup until his minutes reached around 34 to 35 minutes per game.
Still, Leonard had felt good until experiencing stiffness in his knee after Tuesday morning's shootaround. Lue said Leonard isn't scheduled to undergo any medical tests or examination in Los Angeles.
"Sending him back to L.A. because he has better resources for his rehab there," Lue said. "And see what happens after that.
"I mean that's part of the process when you have ACL surgery. It's known to happen to get a little stiffness, so we just got to be smart about it."
Veteran Nicolas Batum isn't concerned about Leonard missing some time or the Clippers needing more time before seeing what they can do at full strength.
"It's going to take at least two months to really get everything in the same groove, get set," Batum said after Tuesday's loss. "That's normal. We've barely had less than three weeks [of] training camp. Only four preseason games. So we're going to be OK when we bring everybody back and going to be ready down the road for sure."
Batum had a message for fans: "Relax."
"We know it's not easy, it's not cool to watch a game like [Tuesday's], and we love the support but we'll be OK," Batum said. "We just need to get through it, keep working, stick together, keep watching film, practice, playing games, and we're going to find a solution and be OK. We have a good staff, perfect coach for that. Perfect players, we'll be fine."