Apart from Warner I'm wondering who the other 3 better openers are. Cowan is about as good as he will ever be and that isn't good enough to make him a monty over Rogers. Watson's form has been terrible and his position in the side in unsettled at best. Some are gearing him to a lower middle order spot so he can give an emphasis to his bowling.
Then there's Hughes whose form is dodgy. Besides we want to make him our permanent no.3 don't we? Or thats the impression Micky Arthur gave just before he made his return. Whats the point in moving him to opener if the situation arose? We'd just give him a new brief even before he settled his present one. Then we'd need another no.3. That'd increase the pressure on Clarke to leave a position where he's made a mountain to one where he's made a molehill.
It might seem we have a heap of openers but really we don't have many options. Thats why I favour Rogers in the squad to act as the replacement opener without disturbing Hughes (or Clarke) or confusing Watson even more about his role. Whatever the hell that happens to be now.