The £12.6m striker saw his form drop alarmingly last season amid accusations he was spending too much time partying.

But now Ferguson has expressed his delight at the reaction of the 29-year-old since he told him to change his ways.

He said: "I told Dwight at the end of the season that either he had to change or he had to go.

"He had had a phenomenal first season and everyone expected him to go from there. So he has to put last season behind him - and I will, too - simply because he never gave himself a chance.

"All the trips to play for Trinidad and Tobago handicapped him and, on his own admission, he wasn't living the right way.

"It's not that Dwight's such a terrible night-lifer. It's more a case of when he does go out he attracts a lot of attention. And the attention is the worst aspect," he added.

"It gets him into the newspapers for the wrong reasons and that creates a lot of pressure for an individual. There were a lot of times last season when Dwight would come in and say 'Honest, gaffer, I did nothing wrong' or 'I was never there, gaffer'.

"The pressure eventually got to him to the point where he wasn't delivering on the pitch. So I had a word with him."

Ferguson believes Yorke is fitter than ever and poised to return to his best form.

He added: "I'm pleased to say that I've been delighted with him in pre-season. Only the other day I took him aside to tell him so.

"Dwight has addressed one of his problems by being prepared to sacrifice playing for his country. That's one part of it.

"The second part is how he looks after himself from here on in. At our first-day fitness test he was the best. He beat David Beckham - and that's saying something.

"He's two yards faster already than he was at any time last season. Dwight is training harder than I've ever seen him. Absolutely superb. I can't fault him.

"Let's see how Dwight goes from here. He's playing for a new contract. Who would want to leave?"