Manchester United boss Sir Alex Ferguson says rotating his squad is a way of keeping his young players happy.

By spreading games around, Ferguson has retained the quality of Ryan Giggs, Paul Scholes and Gary Neville.

"At the same time, he has been able to monitor the development of the likes of Rafael, Jonny Evans, Danny Welbeck and Darron Gibson.

"Unless you utilise a large squad, you're going to lose players because they will want to move on to somewhere they can make some contribution," said Ferguson.