Frederic dropped Gustafsson — who had no NHL fights to his name — with one punch and sent him into concussion protocol.

Trent Frederic scored twice on Saturday afternoon for the Boston Bruins, and he knows he needs to score more. Goals have been few and far between this year for Frederic this year, who says he’s feeling pressure to produce with his contract expiring at the end of this season.

Frederic scored Boston’s first two goals, initially cutting Philadelphia’s 2-0 lead in half with a power-play tally in the second period. His second strike started Boston’s late-game surge.