Being a gunner is more about speed, is it not? I've never seen a gunner pancake a blocker, and you almost always have two guys in on the tackle of the return man. Not only that, but how big is your average return man? If figurs isn't big enough to take down guys that are returning punts, than he shouldn't be in the league. Even if he can't take them out by himself, he can atleast slow them down enough to get some help.
I think he'd be fine if they decided to use him there.