Providing they were all fit, four United stars – Rio Ferdinand, Wayne Rooney, Gary Neville and Alan Smith – would be certainties for the trip, with another two – Phil Neville and Wes Brown – also likely to be included.

Eriksson already knows he will be without his captain and vice-captain as the extended Spanish season ensures David Beckham and Michael Owen will be required for domestic duties.

The presence of either Chelsea or Liverpool in the Champions League Final on May 25 would also prevent any of their players from making the squad, which heads across the Atlantic a day earlier.

Arsenal boss Arsene Wenger has already questioned the wisdom of the trip, with Ferguson adding fuel to the argument with some typically forthright comments.

“It is not a FIFA tournament so we’re not obliged to send our players,” said Ferguson.

“We will have to assess who needs to rest and see who actually wants to go because players don’t always want to.

“Players with clubs at the top of the league will have had a much harder season than others,” quotes The Sun.

However, a furious FA are likely to crack down hard on United if none of their players are made available.

They believe Eriksson has already bent over backwards to accommodate English clubs by refusing to arrange World Cup qualifiers on the official FIFA fixture date in June.

It has been pointed out that even with the tour commitments, English players will now start their summer break a fortnight before most of their European counterparts.

It now seems certain that if Ferguson does refuse to release players without putting them forward for a formal examination by the FA’s medical staff, they will use their own regulations to impose sanctions on the Old Trafford outfit.

FA regulation D1 states: A player selected for an international or other representative team, or tour, or squad, or other call-up arranged by the association shall attend at the time and place notified to the player and comply with the arrangements of the association in every respect save where there is good and sufficient cause not to do so.

D2 says: A club should do all things necessary to ensure that a player referred to in rule D1 complies with the requirements of the association.

D3 adds: Illness or injury shall constitute good and sufficient cause for the purposes of rule D1, where the association is satisfied, following receipt of medical evidence, that such illness or injury is of sufficient seriousness. The player should in any event submit to assessment by a medical advisor appointed by the association.

Failure to comply with these regulations can result in both the club and individual players being fined or reprimanded, although whether this will be enough to dissuade Ferguson from igniting another club versus country feud remains to be seen.

The United boss has never previously taken much consideration of the FA’s feelings, most notably two years ago when he claimed Paul Scholes was not even fit enough to be selected for England’s squad to face Portugal, then promptly selected him for a Premiership encounter with Middlesbrough.

There are few subjects upon which Ferguson and Wenger agree, but one is the major reason why England have embarked on such a tour, just weeks after Eriksson had his wish granted for a four-week break between the end of next season and the start of the World Cup.

“On one hand you want the England national team to have a four-week break before the World Cup but then you don’t want to give them a holiday after a long and exhausting season,” Wenger told the Evening Standard.

“I cannot understand the logic of going to the United States. Half the team will pull out anyway and the other half will be going after having played 55 games.

“I am not at all happy to lose Ashley [Cole] and Sol [Campbell]. But I didn’t organise the tour.

“The most important thing is to give the players a breather. But I think money might come into it.”

Eriksson, however, has defended the decision, saying: “We wanted to play now rather than use empty World Cup qualifying dates in June, to ensure the players have the chance to rest properly over the summer.

“It is a very good opportunity for me to be with the players for a week and to take a close look at some of the newer members of the squad.”