The 24-year-old defenseman Mitchell has played in 13 games this season, recording two assists and accumulating 10 penalty minutes while averaging 15:18 of ice time.
The Boston Bruins acquired Mitchell from the Chicago Blackhawks on June 26 as part of the trade that involved Taylor Hall and Nick Foligno moving to Chicago. The deal also included defenseman Alec Regula coming to Boston.
Mitchell, a second-round pick in the 2017 NHL Entry Draft by the Blackhawks, signed a one-year, one-way contract with the Bruins on July 10, earning $775,000 this season regardless of whether he plays in the NHL or the AHL.
The Boston Bruins currently lead the Eastern Conference's Atlantic Division with a 20-7-6 record and 46 points.
