Liverpool manager Roy Hodgson has stressed he will not risk damaging the club's Barclays Premier League campaign for the sake of progress in Europe.
Hodgson is likely to have to play both legs of their Europa League third-round qualifier against either Macedonian side Rabotnicki or Armenia's Mika without any of his World Cup stars after the club's medical staff warned him about forcing them into action too early after a gruelling and lengthy season.
"Possibly none of our World Cup players will play in the early Europa Cup games if we listen to the advice of the sports science people," said the 62-year-old.
"They are telling me we would be very foolhardy to use players who have only been training for three or four days on the back of the World Cup that early on because that will affect us further on down the road.
"If we feel we are endangering our chances of doing well in the Premier League by risking players in the early stage of the Europa League, it will be a decision the club will have to take. You have to follow the guidance."
Liverpool's England contingent of Steven Gerrard, Jamie Carragher and Glen Johnson, Denmark's Daniel Agger and Slovakia's Martin Skrtel will all return to individual programmes at the club's Melwood training ground in the coming days while a squad made up largely of reserves are still at their Switzerland training camp.
Argentina duo Javier Mascherano and Maxi Rodriguez are due back a week on Monday while Spain's World Cup winners Fernando Torres and Jose Reina and beaten Holland finalists Dirk Kuyt and Ryan Babel do not return until after the first leg has been played.
"Their (medical staff's) advice is to not use these players," added Hodgson, who will at least have new signing Milan Jovanovic available with the possibility of any new arrivals also being utilised.
"If we have enough players to put a team out without them is another question. Things can happen before July 29; we will not be speculating on that and there is no point in me making predictions of what the team will be like for that game.
"The sports science people are advising me not to use the players from the World Cup. Therefore new signings would become important for the Europa League."