Moyes told the Premier League club's website that several of his squad had been contacted about playing in what will be the first British football team at an Olympics in 52 years.
"It would be hard to say to players not to [compete in the Olympics], but in the same breath this [Everton] is their bread and butter and this is where they get paid," said the Scot.
"They do need holidays and they can't then be asking for spare time off that doesn't fit in.
"If they say 'I'm playing in the Olympics then I might need a week off to recover', there can never be anything like that," added the manager.
"We accept international tournaments. What we're willing to do to those boys is give them a bit of extra time off because the players definitely need a holiday," he added.
"But I think the players going to the Olympics will have to consider their own holiday time and it couldn't be eaten into the club's time."
Wales, Scotland and Northern Ireland - who play under their own national identities in international tournaments - have voiced disapproval of a united British team.
Team GB is being managed by former England international Stuart Pearce and England have said players called up for the 2012 European Championships in June will not be selected for the Olympics which start on July 27.
Everton's Jack Rodwell and Ross Barkley have played for Pearce's England Under-21 side and are likely to feature in the Olympic plans.
