Irvine: Cahill transforms Everton options
"With Tim's ability it gives us the opportunity to pick and choose our system more than we have been able to."
Everton's current squad, bolstered over the summer, now has players able to fulfil a wide range of roles in order to service the team.
"It means we can play with one striker with Tim playing behind but there will be plenty of times when we will play with two strikers," said Irvine. "We have the luxury of having a lot of players to choose from and the luxury of being able to switch formations."