Sam Allardyce plans to reprimand Everton's communications team after a timescale of six to eight weeks was put on Gylfi Sigurdsson's recovery.
Sigurdsson suffered a knee injury during Saturday's 2-0 victory over Brighton and Hove Albion in the Premier League.
Everton revealed in a statement on Wednesday the Iceland international would be sidelined for "between six and eight weeks" after consultation with a specialist.
That would make a return before the end of the season unlikely for Sigurdsson, and leave him battling to be fit for the World Cup.
| It is anticipated Gylfi Sigurdsson will be sidelined for between 6-8 weeks with the knee injury he sustained against Brighton.Update March 14, 2018
But Allardyce says that is incorrect, and he is hopeful of having the 28-year-old back before the end of the campaign.
"Whoever gave that statement out is going to get a right telling off because you cannot predict a length of injury in its entirety," Allardyce told a media conference on Thursday.
"You have people who heal quicker. We've got a highly qualified medical staff and equipment to try and speed up any injury.
"I've always felt it's the wrong thing to do, to tag an injury for its time limits because people recover quicker than others.
"For me, it's how the injury is in the next two weeks. When you sustain a knee injury, there's a settling down period immediately afterwards and then it's how quickly the player recovers.
"Gylfi's motivation is to get back playing for us and for Iceland at the World Cup."
Everton take on Stoke City in the Premier League on Saturday.
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