Guardiola is expected to leave Manchester City at the end of the season after 10 years in charge.

On the BBC’s Wayne Rooney Show, the former Manchester United forward drew comparisons to his former boss at Old Trafford, for whom he played between 2004 and 2013.

“I have seen a lot of comparisons to Alex Ferguson,” Rooney said. “I can say Ferguson is the greatest of all time, but Pep, in his generation, is certainly the best by a long way.”

Guardiola has won 17 major trophies – and 20 in all – including six Premier League titles, the Champions League, three FA Cups and five EFL Cups during his 10 years at City.

Ferguson holds the record for the most Premier League titles by some distance, with 13.

“I’ve been looking at people saying how loyal he’s [Guardiola] been for 10 years, which is incredible. But Alex Ferguson has done 26 years,” Rooney added.

“When you actually think of that amount of time, 26 years at one football club, it’s absolutely astonishing.”

Rooney spoke about how difficult it is for a manager as long-serving as Ferguson – who led United from November 1986 to May 2013 – “to maintain hunger and mentality for the game”.

“When Sir Alex took over United, it was a completely different situation,” Rooney said.

“He almost had to build the club up from the ground up to get them to become a successful force in English football again – whereas I think Pep didn’t necessarily have to do that.

“But what he has done in terms of complete and utter dominance… It’s nothing to sniff at.”

Two different managers, two different styles

Ferguson became Manchester United manager after leaving Scottish Premier League side Aberdeen.

He is the most successful manager in British football history, having won 49 trophies, 38 of them at Old Trafford.

Asked if Guardiola and Ferguson used similar playing styles, Rooney said: “Football has changed. It’s different generations with different styles.”

But he said Guardiola’s possession-based football has driven change in the English game.

“I think he has been a breath of fresh air,” he said. “Pep has been incredible, and he has completely changed the face of English football.

“It has changed over the last 10 to 15 years – more foreign players, more foreign managers. But he is the one who has come in and actually changed the whole pyramid, even Sunday league football.

“He’s influenced every aspect of English football. People playing out from the back, kids’ teams playing out from the back.”