The 34-year-old has three fights in his last four games, with the most recent one coming against Carolina Hurricanes forward Micheal Ferland on Tuesday night. The new enforcer role is a concerning one for Backes, who's been diagnosed with three concussions since signing with the Bruins in 2016.
"You start piling them up, it's not fun when, or if, you have a concussion," Backes said in November. "You start adding them up and trying to work through it, if you're multiplying them on top of each other, it starts to get dangerous."
Backes has eclipsed three fights in a season only once over his 13-year career, squaring off with opponents on five occasions during the 2009-10 campaign with the St. Louis Blues, according to Hockey Fights.
With just 14 points in 54 contests this season, Backes is on pace for his least-productive campaign since becoming an NHL regular. He's on the Bruins' books at a $6-million cap hit until 2021.