Pettersson, 19, was selected by the Flyers in the seventh round (No. 198) of the 2014 NHL Draft.
The 5-foot-9, 187-pound defenseman played the past two seasons in the Swedish Hockey League with Linkoping, where he played 62 games. Pettersson represented Sweden at the 2014 World Junior Championship, winning a silver medal.
Right now I'm just happy to be back and get through this season and make sure I do my job. I've never had an issue with having to prove myself again and I'll try to do it again. We'll see where it takes me.
— Defenseman Torey Krug on signing with the Boston Bruins