MILWAUKEE — Celtics assistant coach Micah Shrewsberry is leaving the team to return to Purdue as an assistant coach, according to an NBA source.

Shrewsberry was a member of Celtics coach Brad Stevens’s staff at Butler before serving as an assistant at Purdue from 2011-13. He rejoined Stevens after Stevens was hired by the Celtics prior to the 2013-14 season.

Shrewsberry emerged as one of Stevens’s top lieutenants with the Celtics, playing a key role as one of the architects of Boston’s defense that became one of the best in the NBA.

This season, Purdue lost to eventual national champion Virginia in overtime in the Elite Eight of the NCAA Tournament.


Adam Himmelsbach can be reached at adam.himmelsbach@globe.com. Follow him on Twitter @adamhimmelsbach.