The Merseyside outfit have been challenging for Europe throughout the campaign, and currently sit six points away from Champions League qualification with seven games left to play.
While Moyes began rebuilding the squad last summer, the Scotsman believes that the impending departure of captain Phil Neville and the status of the club's ageing players leave Everton with work to do.
"I do think there is a big rebuilding job to go on at Everton," The Independent quotes Moyes as saying. "With Phil going that is a big piece of the jigsaw which will leave and if we make Europe we are going to have to find a way of bringing in five or six players because of the way your squad is affected.
"We have a few players getting near the end, we have a little bit of an ageing team. We have not invested an awful lot over the last five or six years so we have to now be looking to see how we do that, how we get the team moving forward and get some younger players in as well as developing our own.
"It is a tough act for us at the moment because we are trying to get that balance of keeping up at the top end of the league and obviously having to try to change over the age group of players we have. It happens at all clubs. It all comes to an end and teams continue to evolve."
Meanwhile, Moyes has maintained that he will not discuss the possibility of signing a new contract until the end of the summer.