City go to Upton Park on Saturday for their first game since losing the title after just one season, and Allardyce reckons that the reason United are back at the top of their game again is Alex Ferguson.
The West Ham boss does not hide the fact that he is good friends with Fergie and he knows that the United supremo has suffered setbacks before, but he has the knowhow to bounce back again making sure that United remain the most successful club in English football.
Allardyce also believes that Fergie will remain at number one for some time to come, he told reporters at a press conference: "You're always chasing the master and he has been the master for so long - it is difficult to sustain success against him.
"Whenever he has a challenge, he may lose out once, but he comes back with flying colours. He's had it with Chelsea and before that Arsenal."
Source: United Mad