The Red Devils have already won the Fifa Club World Cup and the Carling Cup this season.
He told the New Statesman: “The thing about cup football is you need to be the best but you also need a lot of luck and I think it’s asking too much for all the games to go your way.
“The one thing I will say is, this squad is the best I have ever had. Every game we play, I feel confident.
“At the moment, every attack fears our defence and every defence fears our midfield and attack. That gives you confidence but it is too tough a call.”