General manager David Griffin told reporters the news at media day on Monday, per Jason Lloyd of the Akron Beacon Journal.
The Cavaliers cannot use the stretch provision to spread Williams' $2.2 million salary over the next three years. They chose not to waive him before the Aug. 31 stretch deadline.
Williams, 33, previously exercised his player option for 2016-17—seemingly indicating he'd come back for a 14th NBA season. Joe Vardon of Cleveland.com reported Williams was strongly considering retirement, but the veteran guard tweeted he would play for one more season on Sept. 21:
Assuming he stays retired, Williams had far greater success than anyone expected when he was plucked out of 2003's second round. He averaged 13.2 points and 4.9 assists over 13 seasons, playing for the Utah Jazz, Milwaukee Bucks, Los Angeles Clippers, Portland Trail Blazers, Minnesota Timberwolves and Charlotte Hornets, in addition to Cleveland.
He spent no more than four seasons with any team but had his most extended run of success with the Cavaliers. The sweet-shooting guard was a 2009 NBA All-Star during LeBron James' first run with the franchise but never quite reached those heights after James' departure. He played for six teams in his final five NBA seasons, signing a two-year deal in Cleveland last summer.
Starting the year as a replacement for Kyrie Irving, Williams began the season well before falling out of the rotation. He finished with averages of 8.2 points and 2.4 assists per game, his worst numbers since he was a rookie. Matthew Dellavedova's playoff spiral opened up a role for Williams during the Cavaliers' NBA Finals comeback against the Golden State Warriors.
"Mo's been in big situations before," coach Tyronn Lue told reporters. "He's been an All-Star. He's played in the Eastern Conference Finals. We just talked about it among myself and my coaching staff just about giving Mo a chance. He came out, and he's been preparing. He's been working hard for the moment."
With the Cavs having already lost Dellavedova to the Milwaukee Bucks, Williams' departure leaves the team with a hole at backup point guard. Cleveland selected Kay Felder in the second round in June's draft, but the team is definitely looking thin compared to last year.
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