The Grant Williams era in Boston appears to be over.
The Celtics are sending the 24-year-old forward to the Dallas Mavericks in a three-team trade, according to The Athletic's Shams Charania. Williams, a restricted free agent, will join Dallas on a four-year contract worth $54 million via sign-and-trade.
Boston will receive two second-round picks and a 2025 second-round pick swap in the deal, per The Boston Globe's Adam Himmelsbach. The San Antonio Spurs are the third team involved and will receive veteran wing Reggie Bullock plus two second-rounders.
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ESPN's Bobby Marks adds that the Celtics will create a TPE (traded player exception) worth about $6.2 million (50 percent of Williams' outgoing salary) in the deal.
Williams averaged career highs in points per game (8.1), rebounds per game (4.6), and assists per game (1.7) while shooting 45.4 percent from the floor (39.4 percent from 3) in 79 games last season. He served as one of the C's top frontcourt defenders and developed into a key depth piece during his four seasons with the team.
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But the Celtics' acquisition of big man Kristaps Porzingis, who reportedly agreed to a two-year, $60 million contract extension with Boston and will make $36 million in 2023-24, made it harder for the team to keep Williams on a long-term deal.
Boston originally selected Williams out of Tennessee with the 22nd overall pick in the 2019 NBA Draft.