The Boston Bruins selected Trotman, a defenseman from Carmel, Indiana, with the final pick (No. 210) in the 2010 NHL Draft, following his first season at Lake Superior State. Trotman spent two more seasons in college before signing with the Bruins on March 24, 2012.
The Bruins assigned him to Providence of the American Hockey League. He earned his first NHL call-up on Dec. 28, 2013, and was scoreless in two games before being returned to Providence. He split 2014-15 between Providence and Boston, and scored his first NHL goal on April 2, 2015, against the Detroit Red Wings.