Former Manchester United full-back Denis Irwin believes that Manchester City will pose the greatest threat to the Old Trafford side's hopes of claiming a 20th league title next season.
Ahead of the opening game of United's pre-season tour of the USA, which takes place against New England Revolution on Wednesday, the Irishman recently told ESPNsoccernet of his belief that, when the real games begin, the team from Manchester's blue half will be the one to watch.
He said: "For the title, I think Manchester City will be a huge threat, particularly if they hang on to (Carlos) Tevez and sign a couple of quality players as well. They are getting better, the noisy neighbours, and it is going to be very interesting in Manchester next year."
United's visit to North America in 2010 saw the debuts in red of two hitherto unproven youngsters. One year on, Chris Smalling has emerged as an able deputy for Rio Ferdinand and Nemanja Vidic, while Javier Hernandez has established himself as a first-choice following a 20-goal debut season in England.
Irwin agrees with the comparisons which have been drawn between Hernandez and Ole Gunnar Solskjaer but adds that he sees the qualities of another of his former teammates in the Mexican.
"I'd compare him to (Andrew) Cole as well. He was such a quick player who made a lot of his own chances because of how fast he was. I think Hernandez is very much like that as well, he is a really rapid player," Irwin explained.
"He is like Ole too, in that he looks to play off the shoulder of the last defender and he knows where the goal is. Ole was a fantastic student of the game while Coley scored some great goals for us so a combination of both those players is really a plus."
Smalling and Hernandez have been joined by David De Gea, Phil Jones and Ashley Young as Sir Alex Ferguson continues to reshape his squad. As youth comes into Old Trafford, a number of experienced faces have left the club and there has been speculation that another, Dimitar Berbatov, may also be sold.
However, despite the omission of the Premier League's joint top-scorer from the matchday squad for the Champions League final, Irwin expects the Bulgarian to remain in Ferguson's plans.
"I know (Berbatov) didn't get much playing time in the last three of four months of the season but he is a very important player for United. You can't just go moving out players willy-nilly. He is a fantastic player and I expect him to stay," said Irwin.
Retirements will deprive United of two of this season's title-winners. Paul Scholes has hung up his boots after 676 matches and will now take on a coaching role with the club. Meanwhile, Irwin compares the task of replacing Edwin van der Sar with that of finding a successor to Peter Schmeichel in 1999, after which a number of goalkeepers were given a chance to claim the number one shirt, with varying degrees of success.
Irwin said:"It's going to be very hard, very, very hard. I remember too well. Big Pete was a monster of a keeper for us. When you get a back four or back five that play so often together, they develop a great understanding. In our case, we knew what he would do on crosses, he was a fantastic shot-stopper.
"Van der Sar had an unbelievably good six seasons at United. He was great with both feet and made very few mistakes which is what you want. He had very good concentration levels as well. Sometimes at United you only have to make one or two saves every game but they are important ones."
One veteran who will continue for at least one more season is Ryan Giggs and Irwin is impressed with the way the veteran Welshman has evolved as a player since he made his debut as a 17-year-old substitute in March 1991.
"He actually came on for me against Everton - it's a long time ago! To play for this club at the highest level for 20 years is some achievement. He was a left winger and then had to kind of reinvent himself a little bit," reflected Irwin.
"The game has got quicker and more physical with bigger players but he has shown he can play off the front man or in central midfield. He played left-back at West Ham (in April) so it just shows the ability he has got."
United's 19th title took the club past Liverpool into first place on the list of English champions. However, hopes of a fourth European Cup triumph were dashed by Barcelona at Wembley.
"We had such a good season," said Irwin. "We won the league by nine points and our home record was great but we came up against a Barcelona team that is probably the best I have seen of any teams, certainly in my day. You just have to look at the names: (Andres) Iniesta, (David) Villa, Xavi, (Lionel) Messi. We got well beaten on the night and I think everybody has held their hands up and said they were much better."
Irwin concedes that the current Barcelona side is playing at a level 'it might take two or three years' to reach. He also admits that the two great United teams for which he played would have taken very different approaches to stopping Pep Guardiola's men.
He said: "The 1994 team, had we played them, would have tried to kick them! The game was different then and we had some tough players: (Roy) Keane, (Paul) Ince, (Steve) Bruce, (Gary) Pallister. Paul Parker was a fantastic man-marker so maybe he could have taken Messi. With Giggs and Kanchelskis we had a lot of good pace as well to go with the tough lads.
"The 1999 side was very attacking. We won the European Cup final despite our two best players not playing. So it's very difficult for me to say but, certainly, if we had played Barcelona in 1994, we would have tried to kick them!"
Catching Barcelona is one of the greatest challenges faced by Ferguson, who will celebrate 25 years as United manager in November. The Scot turns 70 the following month but Irwin is in no doubt that his old boss is ready to take on the test.
"(Ferguson) leads the club by example," reflected Irwin. "He's first into training, his desire and hunger are there to see and, if any player doesn't match that, he will soon on his way. When the players come in for pre-season, he will spell out what is expected of them.
"It's a winning mentality and all of that comes from the manager. His man-management is great and he is steeped in football knowledge as well but it is his determination and desire to win trophy after trophy after trophy every year that comes back every pre-season."
After New England, United face MLS clubs from Seattle and Chicago, followed by the league's all-stars in New Jersey. The tour ends on July 30 with a friendly against Barcelona on the outskirts of Washington, D.C. The encounter will provide another reminder of the benchmark set by the Catalan giants, one which Ferguson will hope to reach in Munich next May.
Before then, domestic duty will take priority for the champions and, while Irwin does not rule out Chelsea, Arsenal or Liverpool from a title race he believes could the tightest in years, of all the pretenders to Manchester United's throne, it is their cross-city rivals who represent the biggest danger.
Andrew Hush is an associate producer on ESPNSoccernet Press Pass, which can be viewed online here. Follow the show on Twitter at www.twitter.com/ESPNPressPass