I don't see a need for a McGrattan on this team. Yes, he's good in fights....when he fights. But other than that, you barely notice him. He doesn't throw his body around and hit people. He not a particularly great skater, nor does he have adequate puck skills. He's not a particularly adept at playing defense. Basically, aside from fighting, he contributes almost nothing.
I would've said the same thing about Clune the first couple of games in, but Clune has shown he can actually be a contributing member of a line and has displayed some solid hockey sense (which has surprised me). In short, if another forward goes down, Clune gives you a lot more ability to absorb some ice time than someone like McGrattan.
This move should probably be permanent.