Grant Williams is reportedly on the move.

According to Shams Charania of The Athletic and Stadium, the fifth-year power forward is being sent from the Boston Celtics to the Dallas Mavericks as part of a three-team sign-and-trade that also includes the San Antonio Spurs. Charania added that Williams is finalizing a four-year, $54 million deal with the Mavs.

The Celtics reportedly received multiple second-round draft picks in the deal, while the Spurs acquired veteran forward Reggie Bullock and an unprotected pick swap from Dallas in 2030.

Williams was a restricted free agent after the Celtics extended an $8.4 million qualifying offer to him on June 29. After drawing significant interest on the open market, he’s ready to leave the team that drafted him 22nd overall in 2019.

Williams averaged career highs of 8.1 points, 4.6 rebounds and 1.7 assists while shooting 39.5 percent from beyond the arc in 79 games this season. He also was one of Boston’s top frontcourt defenders and a key depth piece. However, he fell out of the postseason rotation, posting five DNPs in 20 games with just four double-digit scoring performances.

The 24-year-old underwent hand surgery in June to repair a torn ligament but expects to be recovered in time for training camp in the fall. He originally suffered the injury in March but played through it as the Celtics made a run to the Eastern Conference Finals, where they fell to the Miami Heat in seven games.

Adding Williams gives the Mavericks a rugged and versatile defender in the frontcourt who should help the team compete for a postseason spot next season after falling short of the playoffs this past year.