The Celtics have bolstered their coaching staff by hiring longtime assistant and NBA veteran Sam Cassell to serve as Joe Mazzulla’s top assistant, a league source confirmed Sunday night.
Cassell, 53, a three-time champion and backup point guard on the Celtics’ 2008 title team, has been a prime head coaching candidate for several years, interviewing for openings with the Clippers, Jazz, and Rockets. But he has yet to be hired for a top job.
He has been an NBA assistant since joining the Wizards in that role in 2009. He worked under former Celtics coach Doc Rivers with the Clippers from 2014-20 and spent the last three seasons on Rivers’s staff with the 76ers. Rivers was fired by Philadelphia last month.
Cassell will bring the Celtics a level of experience as an NBA player and coach that was lacking for much of this past season.
Last summer, head coach Ime Udoka’s lead assistant, Will Hardy, was hired to coach the Jazz. In September, Udoka was suspended for having an inappropriate relationship with a subordinate team employee and was replaced on an interim basis by Mazzulla, who was named full-time coach and received a contract extension after the team parted ways with Udoka in February. In March, assistant coach Damon Stoudamire, the lone member of the staff with extensive experience as an NBA player, was hired to coach Georgia Tech.
Before adding Cassell, Boston had filled all of those vacancies internally and not made any outside hires.
On Thursday, Celtics president of basketball operations Brad Stevens hinted that a high-profile NBA assistant could be joining the team shortly.
“We’re going to look for at least one addition to the bench, and [Mazzulla] will lead this charge,” Stevens said. “We’ll look for somebody that has a lot of NBA experience, for sure.”
Mazzulla could soon have other vacancies to fill, with several assistants who were hired by Udoka in 2021 rumored to be joining him with the Houston Rockets. But the addition of Cassell in the No. 2 spot will give the staff an instant boost.