Celtics Rumors: Robert Williams III Had PRP Injection After Undergoing Knee Surgery

Boston Celtics center Robert Williams III is reportedly out indefinitely after receiving a platelet-rich plasma (PRP) injection in his injured left knee on Monday.

Shams Charania of Stadium and The Athletic reported the update Tuesday, noting the Celtics hope Williams, who underwent knee surgery in late September, can return for the second half of the 2022-23 NBA season:

The 25-year-old former Texas A&M standout has made steady progress across four NBA seasons since being selected in the first round of the 2018 draft.

He's coming off a career-best 2021-22 campaign that saw him average 10.0 points, 9.6 rebounds, 2.2 blocks and 2.0 assists while shooting 73.6 percent from the field across 61 games. He earned a spot on the NBA All-Defensive second team.

Williams had surgery on the knee in March to repair a torn meniscus. He returned just three weeks later for the Celtics' playoff run that ended with an appearance in the 2022 NBA Finals, where they came up short against the Golden State Warriors.

Last month, the Louisiana native said he didn't regret coming back quickly from the March procedure.

"I was 24 years old; my dream was to play in the Finals," Williams told reporters. "Can't regret that s--t."

He's not the only member of the Celtics frontcourt to miss the start of the season. Forward Danilo Gallinari suffered a torn ACL while playing for the Italian national team in early September and could miss all of 2022-23.

Boston signed veteran power forward Blake Griffin to provide depth behind the starting tandem of Jayson Tatum and Al Horford.

The Celtics should have enough of both high-end talent and depth to make up for Williams' absence during the regular season, but his presence, especially at the defensive end, will be sorely missed if he doesn't make it back in time for the playoffs.

A clearer timetable for his return figures to become available around the new year.

For now, the reigning Eastern Conference champions will move forward without him beginning with their season-opening clash with the Philadelphia 76ers on Tuesday night at TD Garden.