The 31-year old attacking midfielder has been out of action in recent matches with a foot injury and said in an interview with The World Game that he would not return home for friendlies in June.
Moyes said it was a smart choice by Cahill who really needs to get back to his best and can achieve that by staying with his club.
"He definitely needs a break because he played in the World Cup and then he went to the Asian Games. I don't think that's helpful, in fact it's really hindered him in my eyes," Moyes said.
"Because of that I think he needs to start looking after himself, to get himself in condition. He's been really good for Everton but Everton have also been really good for him as well so I think it's important he does look at the club and I think because of that he will probably not get involved in any of the friendlies in Australia."