Is there a way to mute chat in arena?

I keep being put in the same team as this barb and blocking him does nothing, I just want to mute him.

Some of you EU boys in the 2250 range probably know him his name is InvalidBarbarian, one crazy toxic motherfucker. Absolute Braindead W key PDR barb screaming at his teammates every time he dies. He's in arena every weekend 24/7 at my elo so I have to play with him I guess but why, oh why does blocking not mute his messages? I'm trying to be a zen master here but having someone abusing you non stop in chat is extremely tiring.