There is the occasional scalper but most of the tickets are sold out before the game so make sure they accompany you to the gate before you hand over any money.

It is very hard to get tickets and you should have one before you go to the game but at worst case this is an option to get tickets.

I've never dealt with scalpers there because I always come prepared with tickets to the game. Tickets are very hard to come by in the first place as evident by the incredibly long season ticket waiting list. So fans aren't likely to part with tickets cause they know the experience of going is priceless.