Manchester United defender John O'Shea admits manager Sir Alex Ferguson's hunger for success amazes him.

And with his manager raising the prospect of carrying on until he reaches the magical 25-year milestone, O'Shea has nothing but praise for Ferguson's commitment to the United cause.

"It is an amazing for someone to be able sustain such a hunger and desire to be the best for so long," said the Republic of Ireland international.

"The manager tries to put that into every player and every squad during every year and in every team he has built.

"You know he is always going to be driving you on. That aspect of his management has always stayed the same. If anything, from what I have witnessed, it has got stronger and stronger. That is what he wants to continue."