Grant Williams ‘headed to Mavericks on a four-year $54 million deal, after Celtics three-team trade

The Dallas Mavericks have agreed to a four-year, $54million deal to acquire restricted free agent forward Grant Williams as part of a three-team sign-and-trade with the Boston Celtics and San Antonio Spurs, according to multiple reports.

San Antonio will receive forward Reggie Bullock and an unprotected first-round pick swap in 2030 from the Mavericks. 

Boston will receive multiple second round-draft picks and a $6.2 million trade exception.

Williams, has spent four seasons with the Celtics since being a first-round pick in 2019 out of Tennessee. He averaged 8.1 points, 4.6 rebounds and shot 39.5% from 3-point range in 79 games -23 starts- last season.

The 24-year-old Williams has career averages of 6.2 points and 3.4 rebounds in 288 games (58 starts).

Williams averaged 8.1 points, 4.6 rebounds and shot 39.5% from 3-point range last season

The Mavericks are also set to send Reggie Bullock to the San Antonio Spurs in the deal

He recently underwent surgery on his left-hand last month and is expected to be fine before the start of training camp.

Williams is the second key player Boston has traded this offseason. The team previously dealt guard Marcus Smart, the NBA Defensive Player of the Year for 2021-22, to the Memphis Grizzlies.

Teams officially can’t sign free agents or formally announce trades until Thursday.

Bullock, 32, spent the past two seasons of his 10-year NBA with the Mavericks. He averaged 7.2 points and 3.6 rebounds in 78 games (55 starts) last season.

Bullock made 151 3-pointers last season, second most in his career behind the 163 he made for the New York Knicks in the 2020-21 campaign. He has made 852 career treys in 512 games (294 starts) with six teams.