Ryan Giggs believes it is essential Wayne Rooney and Manchester United’s other World Cup players come back refreshed from their break.
The club’s record appearance holder knows it is imperative to get off to a good start in August if they are to regain the crown.
Rooney, Michael Carrick, Nemanja Vidic, Patrice Evra and Ji-Sung Park are all absent from United’s five-match summer tour, beginning with a match against Celtic tonight.
Giggs said: “It is always difficult after a World Cup, because the players who have been involved in the tournament have time off.
“You just hope there is no hangover and everyone can hit the ground running.”
Rooney and the rest are due to return 12 days before the Community Shield match against Chelsea on August 8.
And manager Sir Alex Ferguson believes Rooney will soon shake off the frustration of his disappointing World Cup performance.
Ferguson said: “I don’t expect a hangover. I think there’ll still be a bit of disappointment in the lad.
“I think all the players coming back from the World Cup who didn’t do well, who didn’t reach their expectations may I say, will feel that they’ve missed something.
“That’s because the World Cup’s only once every four years. That’s the horrible part of that tournament.
“We have several players who have come back very, very disappointed. We’ve Patrice Evra, for instance, Wayne Rooney of course, and Nemanja Vidic.”
With Vidic absent and Rio Ferdinand injured, former Fulham defender Chris Smalling could be handed a run-out against Neil Lennon’s side.
The 22-man United squad were heading for Toronto last night after a four-day training camp in humid conditions in Chicago.
In readiness for the match against Celtic, the artificial pitch at the Rogers Centre is being replaced by grass.
Meanwhile, in a move that will no doubt send shivers down green-and-gold spines — let alone the rest of the Premier League — Manchester United yesterday unveiled their new shirt and sponsor in Chicago.
The £80m deal with the global insurer Aon, spread over four years, is believed to be one of the most lucrative in the world and more than double Manchester City’s income from their deal with Eihad Airways.
Everyone of Aon’s 36,000 employees is to receive a United shirt after the completion of a deal that reportedly began when the club sent out a shirt to the company’s chief executive.
The famous red top had been imprinted with the Aon logo, along with an invitation to the company to become involved in the competition to succeed AIG as shirt sponsor.
The US-based firm, which has offices in 120 countries, decided that United’s global appeal was unmatched by any other form of advertising or sponsorship.
With the Red Devils still able to attract such lucrative sponsorship deals, it can only make the Glazer family ever more determined to maintain their control of the club.