Tillman is in the starting lineup for Tuesday's game against the Bucks, Justin Turpin of WEEI.com reports.
Tillman will move to the starting lineup Tuesday and anchor the frontcourt in a game where Boston will miss Al Horford (toe) and Kristaps Porzingis (hamstring). Tillman is averaging 7.4 points and 6.1 rebounds per game as a starter this season, though it'll be only his second one in a Boston uniform.