I think there is a mental aspect to the selections here as well. First game of the World Cup. First game to show what we've got against a team we've recently struggled to beat convincingly. I want to see essentially our first XV starting. Barnes, Burgess, the other forwards, etc can get time at the end of the game, as long as we are in a good position.
Italy and Ireland are our big pool games and I don't want to take any chances. The Russia/USA games will be perfect for these guys coming back from injury to get a start, and along with some minutes in the first two games will put them in good stead for the knockout rounds.