Leicester City striker Jamie Vardy and defender Harry Maguire are likely to miss the club's Premier League opener against Manchester United on August 10, manager Claude Puel has said.
The England duo are yet to return to training with Leicester after a demanding World Cup in which Maguire featured in all seven matches as Gareth Southgate's side reached the semi-finals of the tournament in Russia.
"If we are serious I think they cannot participate in the first game, with just five days training with the team," Puel told reporters. "They normally need more time, but we will see together with calm.
"We don't rush these players. It is important after the World Cup to work but also come back with the team and live with the team to find again the atmosphere of the club and the squad.
"Of course Jamie and Harry are valuable players for us but we need to protect them. If they are available to play in their minds it is a good thing... but we have to take a protective decision from us."
United manager Jose Mourinho has also said that several of the team's World Cup participants are likely to be absent when Leicester visit Old Trafford in eight days' time.
Leicester, who drew 1-1 with Spanish club Valencia in a friendly on Wednesday, will play French top-flight side Lille in their final pre-season fixture on Saturday.