Gary Neville believes that it will be a "miracle" if Manchester City fail to win the treble this season.

The Citizens were crowned champions of the Premier League for a third season in a row after second-placed Arsenal suffered a 1-0 away defeat against Nottingham Forest on Saturday.

Pep Guardiola's side are on the cusp of greatness as they chase down a historic treble, with a Champions League final and FA Cup final against Inter Milan and Manchester United respectively to look forward to next month.

Man United are the only English club to ever win the Premier League, Champions League and FA Cup in the same season, completing the remarkable feat in the 1998-99 campaign under Sir Alex Ferguson.

Neville was part of that successful treble-winning squad and he feels that the Red Devils' noisy neighbours are in a strong position to win the same three trophies this term, stating that it would be a "massive disappointment" if they fell short at this late stage.

Speaking to Sky Sports ahead of Man City's Premier League clash with Chelsea at the Etihad Stadium on Sunday, Neville said: "I think for the City now not to win the treble with Manchester United and Inter Milan in front of them will be a massive disappointment.

"They're strong favourites in both games, they're in great form. They've got everything going right for them. It'd be a miracle if you don't win the treble in my eyes.

"That's not me putting pressure on them, but you look at Manchester City they just destroyed Real Madrid with multiple Champions League winners in their team the other night [at the Etihad]. So I don't think they're going to fear Inter Milan they're not going to fear Manchester United.

"Anything can happen in the final we know that. But if Manchester City play at that level, then those two teams are in big trouble. I don't know what the odds are for them to be treble winners, but they'll be odds on favourites."

Neville added: "Only Sir Alex Ferguson has ever won [the treble], has ever done this before as a manager. Pep Guardiola would be a worthy companion of Sir Alex Ferguson, and these players that have played this season would be worthy companion.

"That doesn't mean to say I want to do it by the way! I'd love Manchester United to beat them in the FA Cup final of course or Inter Milan (in the Champions League). But if they were to do it, they will be worthy companions because of the levels that they've reached and the level that this manager has reached here."

With regards to next season's Premier League, Neville believes that Liverpool are best placed to challenge Man City for the title having previously demonstrated they can push the Citizens all the way in recent years, albeit falling "below the standards" this term.

"The team that have got an alignment of quality and mentality (can challenge Man City)," said Neville. "Manchester City's players have real quality, that's goes without saying, but in the most difficult moments of the season in the Premier League, they're able to get a run together and come through difficult challenges.

"Obviously that takes a lot, it takes the manager as well who can guide them through moments and bring that stability, and the other clubs have got a look at that same model.

"It happened at Manchester United for many years under Sir Alex Ferguson, it happened with Liverpool under Bob Paisley and Bill Shankly, great managers. Arsene Wenger had a great period at Arsenal. You've got to be a great manager and you've got to have a great group of players to be able to do it consistently like they have and other teams have got to aspire to that.

"At this moment in time, the one who has proved it over last five, six years is Liverpool. I know Arsenal have run City close this year, but the only team that I can say at the moment that have demonstrated that they can go close to Pep Guardiola's Manchester City is Jurgen Klopp and Liverpool.

"I know they've dropped well below the standards this season, but you [wonder] whether they're going to get back to those standards next season because they have proven they can do that before."

Man City will be looking to extend their impressive unbeaten run across all competitions to 24 matches when they play host to Chelsea, who have lost all three previous meetings with the Citizens this season without scoring.