Gary Neville believes Manchester City are "out of this world" and could have the greatest manager in the history of the sport.
City claimed their fourth successive Carabao Cup trophy with a 1-0 win against Tottenham on Sunday and are set to claim their third Premier League title in four years.
Guardiola's side could complete the Treble after reaching the Champions League semi-finals and are set to face Paris Saint-Germain in the first leg at the Parc des Princes on Wednesday.
"You just have to recognise Man City's outstanding football, the outstanding achievement of winning this trophy four times on the bounce," said Neville. "Pep Guardiola has an outstanding record in cup competitions, it's 14 victories and one defeat in 15 finals, it's absolutely out of this world. The football they play is magnificent, it really is.
Gary Neville won 20 trophies at Man Utd under Sir Alex Ferguson, including eight Premier League titles and two Champions League titles.
"I think Man City may have the greatest manager of all time and we'll look back in 10, 15, 20 years' time… just the way he has infiltrated countries, dominated football but also influenced others, I don't think I've ever seen it.
"You look at how he's won in three different countries, he's now dominating in this country - he's going to win the league title in the next few weeks, that's three in five years and these are massive achievements.
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"Playing the way they play as well, which is with technical players, dominating possession. The big one is the Champions League and it's a huge couple of weeks coming up against Paris Saint-Germain because if they were to win that, then they would have a great chance.
I think Man City may have the greatest manager of all time
"That would be the cherry on the icing on the top of the cake of Guardiola's reign at Man City because I don't think he can leave without winning it. It would feel incomplete if he left this country without winning the Champions League.
"I know that happened in Germany, but here, Man City will give him the time to do it and it almost feels like he has to so he can say that the job is done."
However, Neville was far from impressed with Spurs' current situation after failing to claim their first silverware in 13 years. "Tottenham were quite passive for the whole game. It was beyond them really.
"A dispirited performance in some ways, in a final, which is maybe a little unfair because you're playing against a team like City. But Spurs have got some fantastic players, and I expected a little bit more from them.
They look like a team who are now reacting to what the other team do, rather than having their own idea
"They've obviously lost their manager this week and it's been an incredibly difficult week for most clubs who have been dealing with this issue of the European Super League, we don't know what impact that has had. Losing their manager, playing against an incredible team, all those things are factors.
"But they've lost their coach. Mauricio Pochettino was a great coach for many of these players and they've just lost that ability to understand how to play with each other, they look like a team who are now reacting to what the other team do, rather than having their own idea.
"When I used to watch Spurs under Pochettino, I always thought that there was a plan, an idea and they've gone on to become a group of players who don't have an idea at this moment in time. I think they're going to need a new coach to get that back."