Jamie Redknapp labelled Pep Guardiola the greatest manager in history ahead of Sir Alex Ferguson after he guided Manchester City to their fifth Premier League title in six years.
Guardiola's side celebrated their latest title triumph with a 1-0 win over Chelsea on Sunday after Arsenal's 1-0 loss to Nottingham Forest a day earlier had confirmed them as champions.
Former Barcelona and Bayern Munich boss Guardiola has now won 11 league titles in 14 seasons in management, joining Manchester United legend Ferguson as one of only two managers to have won the Premier League crown in three consecutive years.
Redknapp believes City boss Guardiola is ahead of 13-time title winner Ferguson, however, by virtue of how his preferred playing style has transformed modern football.
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"I think he's the greatest ever and why I say that is that he has changed football," said the Sky Sports pundit as City celebrated their success at the Etihad Stadium.
"There have been some great managers. You go through history, Arrigo Sacchi, what he did with AC Milan, Johan Cruyff… Managers who have changed things forever, and he is certainly one of them.
"When you go and watch football now, be it grassroots or whatever, everybody plays the Pep way. People play out from the back when we thought it is impossible.
"He has changed peoples' perception of the game. You have midfield players and defenders going into different areas, playing out, splitting defences, and for me he is the greatest ever.
"He has won 11 domestic titles in the 14 years he's been a manager, 28 major trophies. You can talk about Sir Alex Ferguson, Bill Shankly as well. There have been some amazing managers.
"But for me he has changed football forever."
Roy Keane stopped short of calling Guardiola the outright greatest but, like Redknapp, the former Manchester United captain was full of praise for the 52-year-old City manager's impact.
"He's up there with the greatest, without a doubt in my mind," Keane said on Sky Sports. "The fact is he is working with talented players, but you've still got to manage them and their egos.
"He likes to challenge them, he's kept that hunger and he looks fit as a fiddle, Pep, so he obviously looks after himself. He looks like a healthy man and he's enjoying it.
"We talk about the important players, but I think he is the most important man at this football club, I really do."
Micah Richards, meanwhile, agreed with Redknapp on how Guardiola has changed football but insisted the City boss remains behind Ferguson due to the sheer number of titles the Scot won.
"Jamie is right, he has changed the way football is played and seen, but Fergie, to get 13 titles, that is some record," Richards said on Sky Sports.
"In terms of what the players do on the pitch, I would say Pep's ahead, and the way he evolves and constantly seems to be ahead of the game.
"But Sir Alex Ferguson, what he did at Man Utd, at a time when there were so many competitors, is still up there, for me, as the greatest."
Keane emphasised the importance of Guardiola's willingness to evolve and keep his players hungry and motivated, adding: "I think that's the challenge Pep has had over the last few years.
"City's recruitment has been fantastic, but the way they have moved players on as well. He has kept the hunger in the group.
"We saw him earlier in the season upsetting plenty of players - [Kevin] De Bruyne, [Kyle] Walker, [John] Stones. He got rid of [Joao] Cancelo and moved [Gabriel] Jesus on.
"People said the squad was too small but he knows what he is doing. He has done it consistently and that's a sign of greatness, to keep winning. What he's doing, the style of play, the hunger.
"We see now the enjoyment he's getting. It's like his first title. Amazing."
'Might Pep fancy something different?'
Guardiola has been at City for seven years and penned a two-year contract extension at the Etihad Stadium in November, but Keane wonders if Champions League success in next month's final against Inter Milan could tempt him to consider his long-term future.
He said: "What if they won the Champions League? Pep might just say I've won the league, he's got his hands on all the domestic trophies and then the Champions League.
"Would he then, in the next year or two maybe, fancy something different?"
When asked why he'd leave City with all their success, Keane added: "A new challenge. Seeing what we've seen recently he still has that hunger. It's the perfect fit. But it might just be for something different.
"He had that at Barcelona. He had a lot of great support at Bayern Munich. He's worked at a lot of great clubs before and fancied a change.
"However, clearly, at the moment, City is the right fit for him in terms of managing the team and the people he is working upstairs with. Obviously, he's got a good rapport with them, so why would he go?
"Maybe if he won the Champions League he might just fancy something new."
Asked whether Guardiola's eventual exit will break City's dominance, Redknapp added: "It will give everyone else a chance, that's for sure. Because whoever comes in next will want to change things and imprint his own style of football.
"There's only so many managers like him. Look at what happened to Man Utd after Sir Alex Ferguson went. The most important thing is to have the right manager who sets the right culture.
"You have to fear them and respect them. I think that's exactly what he does."
What's next for Man City?
The final day of the Premier League season is on May 28 with every game kicking off at 4.30pm. Free match highlights will be published across Sky Sports' digital platforms shortly after full-time.
Before that, Man City head to Brighton on Wednesday - live on Sky Sports - then finish their Premier League campaign away to Brentford.
City then have the FA Cup final against Man Utd at Wembley on June 3 before the Champions League final against Inter Milan on June 10 in Istanbul.