LA Clippers star Kawhi Leonard will be sidelined indefinitely to begin the NBA season as he rehabilitates from inflammation in his right knee, sources told ESPN on Thursday.

The Clippers and Leonard are in the midst of a rehab process for the two-time NBA Finals MVP that is aimed to bring sustainability for him on the court through the season, and the franchise will be diligent and cautious to ensure his fitness long-term.

Leonard, 33, has neither played during the Clippers' entire preseason -- which concludes Thursday against the Sacramento Kings -- nor has he participated in any activity involving on-court contact during training camp.

"He has not been a part of what we've been doing on a daily basis," Clippers assistant coach Brian Shaw said after Wednesday's practice. "I know the company line has been that we're going to be patient with him, so he's doing everything that he can to rehab it and strengthen that knee on his own with our medical staff. And we're just dealing with the guys that we have [available]."

In Leonard's absence, James Harden, who feels more comfortable this season after having a full training camp, will be relied upon to shoulder much of the offensive load and be the team leader. He joined the franchise last year during an early season trade from Philadelphia and had to adapt alongside Leonard, Paul George and Russell Westbrook.

With George now in Philadelphia and Westbrook in Denver, Harden will try to be a playmaker for the likes of Ivica Zubac, Norman Powell and Terance Mann.

Harden has said that Leonard needs to take all the time he needs to return and be healthy for late in the season.

Leonard began to experience inflammation in his surgically repaired right knee following a win at Charlotte on March 31. He missed the final eight games of last regular season and was limited to two games in the six-game, first-round loss to Dallas in the postseason.

Leonard and the Clippers have gone through a variety of medical treatments to control the inflammation since the end of last season. Lawrence Frank, president of basketball operations, said at the start of training camp that the inflammation had gone down significantly since last postseason, but that the team wanted to get the franchise star's knee to 100% and would take every precaution.

When asked if he could have to deal with the inflammation coming up for the rest of his career, Leonard said that is a possibility but that the medical staff has got a better handle on it and is trying to ensure that isn't the case.

Leonard, who sat out the entire 2021-22 season due to a torn ACL in his right knee, has missed 179 of a possible 435 games since joining the Clippers in 2019.

He played in 52 regular-season games in 2022-23. After he tore his right meniscus during the 2023 first-round playoff series against Phoenix, Leonard played in 68 regular-season games last season -- his most since the 2016-17 season -- and averaged 23.7 points, 6.1 rebounds, 3.6 assists and 1.6 steals while earning his sixth All-Star nod.

The Clippers play the Phoenix Suns on Oct. 23 in the Intuit Dome's first regular-season basketball game.