Robert Williams III Mike Watters-USA TODAY Sports

After agreeing to a four-year contract extension with Marcus Smart earlier this week, the Celtics reached a deal to extend another rotation player through 2025-26. The team is in agreement with big man Robert Williams on a four-year, $54M deal, agent Kevin Bradbury tells ESPN’s Adrian Wojnarowski.

Williams, who will turn 24 in October, saw limited playing time in his first two NBA seasons, partly due to injuries, but emerged as a regular contributor for Boston in 2020-21. In 52 games (18.9 MPG), including 13 starts, he averaged 8.0 PPG, 6.9 RPG and 1.8 BPG. His impressive .721 FG% was right in line with his career rate (.720).

Despite only playing in 113 regular-season games to date, Williams has flashed impressive potential on both ends of the court and brings plenty of athleticism to the Celtics frontcourt. As Wojnarowski notes, the new four-year deal will put the former Texas A&M standout in the top half of NBA centers by annual salary, but he has the ability to outplay it if he stays healthy and continues to improve.

The timing of the deal is interesting. Typically, players eligible for rookie scale extensions reach deals closer to the October deadline unless they’re obvious max-salary players like Luka Doncic, Trae Young and Shai Gilgeous-Alexander. Williams – the fourth player to receive a rookie scale extension in 2021 – is the first one of those four to agree to a deal worth less than the max.

The fact that the Celtics were willing to sign off on a new deal for Williams nearly two months ahead of the deadline signals that they were eager to get the young center locked up and were comfortable with the price point.

The extensions for Smart and Williams will all but assure Boston enters the 2022 offseason as an over-the-cap team, barring some major roster moves between now and then.

More must-reads:

TODAY'S BEST
Former NFL player has major warning for Steelers QB Justin Fields: 'You can't fall into this'
Watch: Brad Marchand hurdle Panthers player on Charlie Coyle goal
Pressure mounts on Nuggets as Nikola Jokic wins third MVP Award
Pirates announce date for 2023 No. 1 overall pick's MLB debut
LeBron James rues 'missed opportunities' against Nuggets
Cardinals star gives update on timeline for injury rehab
Police investigating Patrick Beverley incident
J.J. Watt addresses possibly ending retirement to play for Texans
Inter Miami's Lionel Messi could surpass two major MLS records
Reporter weighs in on potential Giants quarterback controversy
Cowboys to release veteran WR
Lakers want Anthony Davis' opinion in search for next head coach
Patriots exec explains why team drafted two QBs in 2024 NFL Draft
Borussia Dortmund legend 'considering' move to MLS
NHL announces Ted Lindsay Award finalists
Mavericks' Luka Doncic lists Thunder swingman among best perimeter defenders in NBA
Cowboys reportedly meeting with recently released veteran WR
Joe Burrow shares 'support' for Bengals who requested trades
Dodgers star latest victim of announcers jinx
Mike Conley discusses what makes Anthony Edwards so special

Want more Celtics news?

Join the hundreds of thousands of fans who start their day with Yardbarker's Morning Bark, the best newsletter in sports.