Russell Westbrook believes the Los Angeles Clippers were missing "the best in the world" as Kawhi Leonard sat out a Game 3 defeat to the Phoenix Suns.

Devin Booker scored 45 points as the Suns beat the Clippers 129-124 on Thursday to take a 2-1 lead, and only the Phoenix star is scoring more points so far in the postseason (36.3 per game) than Leonard (34.5).

But Leonard was not on the floor, watching instead from the sideline due to a knee injury.

The setback was only reported hours before the game in Los Angeles, although it was quickly clarified it was not related to the ACL injury that saw him miss the whole of last season.

Leonard could be back for Game 4, but his absence was a blow – especially as the Clippers came so close to beating the Suns even without him.

"I just feel sorry for him," team-mate Westbrook said. "He probably was playing his best basketball in a while, probably the best in the world, honestly. It just sucks just for him mentally.

"But it was good to see him be around and communicate with us on the bench. Hopefully we can see how he's feeling and see what's next.

"If he's not back, we have to rally around each other, support each other, find ways to make something happen. It's a series. First to four. Get ready for Saturday afternoon."

Coach Ty Lue added of the injury: "It's very deflating. I think more so for Kawhi.

"You have a guy who's coming off ACL, hasn't missed a rehab session, eats right, eats clean, does everything he can for his body, works extremely hard to get to this point. Then you have something like this happen.

"So, it's tough for him, for all the work that he puts in. I feel bad for him."