Getty Joe Mazzulla and Jaylen Brown of the Boston Celtics during an NBA game. There has been growing speculation around the Boston Celtics about the future of Jaylen Brown . However, it seems like the Celtics could be losing two key people this offseason. According to Celtics Blog’s Noa Dalzell , the Celtics are in danger of losing assistant coaches Tony Dobbins and Tyler Lashbrook. Dobbins is one of the finalists for the Portland Trail Blazers head coaching job, while Lashbrook is a finalist