More from the Blackburn manager:
"I think winning another Champions League is something he [Ferguson] feels he would like to do.
"He'll enjoy winning the Premier League, which I suspect he will do, but the Champions League will always be there for a club such as United and I think Sir Alex will keep going until he feels he hasn't got the energy to keep challenging for the Champions League.
"That's the great strength of Sir Alex Ferguson: he's never stood still, never just banked on doing what got him results in the past. He's always looked to the future. The way the club is run and the players are prepared is certainly different from when I was there.
"Sir Alex has always taken great pride in building and dismantling teams and another great strength of his has always been getting the right players for the right time, the right decade."
His own prospects:
"I want to get as far as my ability will allow me to go.
"If I do a good job here [at Blackburn], which at the moment I think I'm doing, we'll have to see what happens in the future.
"I'm very happy here. I've got a good board, chairman and players and I'm excited with the squad I've built. I think it's one of the best squads that Blackburn has had for many years so there's a big challenge here, but a big job is something I think all managers aspire to.
"Whether or not it's a realistic target for the majority of them, who knows, but I won't be fazed by any job I'm faced with.
"You have to have confidence in your own ability and philosophy of how the game should be played and how you approach getting the best out of a group of players and you back yourself in that respect. I have seen it work in my previous job with Wales, I've seen it work here and I know if I was at a different club it would work.
"When Sir Alex makes his decision to leave, I'm sure there will be a hell of a lot of applications falling on David Gill's desk. They will come from worldwide, they won't just come from the Premiership. It's a fantastic job and Sir Alex is doing fantastically in it."
The Guardian publish odds on the next United manager:
6-1 Mark Hughes, Martin O'Neill
7-1 Roy Keane
8-1 Carlos Queiroz
16-1 Jose Mourinho, Marcello Lippi
20-1 Guus Hiddink, Sam Allardyce, Luiz Felipe Scolari, Sven-Goran Eriksson
25-1 David Moyes
33-1 Fabio Capello, Steve McClaren, Gordon Strachan
66-1 Bryan Robson, Paul Ince, Steve Bruce
100-1 Darren Ferguson