When children line up on the playground to have a kick-around, very few request to play the position of full-back.
It is, perhaps, the least glamorous role, and the one that often receives the least credit. But it can be one of the utmost importance to a team.
Manchester United have been blessed with many elite players to have fulfilled the role, the likes of Tony Dunne, Denis Irwin and Gary Neville immediately come to mind.
Here are the Red Devils' 10 best of all time.