It wasn't obvious to me tbh. Several here suggested Coleman as a right sided centre back in a back 3 over the last couple of years but I just don't see him as having the attributes needed, and have said so. Obviously I'd be very happy to be proven wrong.
Yer man O'Connell at Sheffield United seems to be setting a good example / template of the role though - at times he's like on overlapping full back he gets so far forward in wide positions, which is rare to see in a back 3 player. So, yeah, Coleman can definitely do that part. Will an Irish third centre-back ever be given license to attack at will? Will an Irish midfield ever afford us that luxury?
On a kind of related note McCarthy must have been smoking dope prior to Geneva when he picked Stevens as the left sided third centre back in the starting XI. If you're looking for a stick to beat Mick with it's this rather than not picking Coleman in a similar (right sided) role.