one of the biggest falacies in sport imo.
Rooney and Wes Brown are both supposed to be pretty good boxers, so I reckon a game of rugger bugger wouldnt be that taxing on em.
Duncan Ferguson would probably have knocked most rugby players out before they knew what hit em.
although I admit, most footballers couldn't handle the post match anal play enjoyed by so many rugby players around the world (except Ashley Cole and Jermaine Jennas of course).