An athletic 6'10, 235 center out of Boston College, Williams' NBA career was derailed by a series of discipline problems in New Jersey.
But in a stint with the Mavericks' D-League affiliates, the Texas Legends, last season, Williams turned his career around. His work ethic impressed the Legends' coaching staff and he finished second in the NBDL for Defensive Player of the Year voting, behind Chris Johnson, who was called up by the Portland Trail Blazers.
In three seasons with New Jersey, Williams averaged 4.3 points, 3.5 rebounds and 1.4 blocks in only 14.8 minutes a game.
Williams had been playing with the Israeli club Maccabi Haifa, but he should be in a Dallas uniform by the Mavericks' second pre-season game against Oklahoma City on Wednesday.
He will compete with Ian Mahinmi for minutes behind Brendan Haywood this season.