Emile Heskey's recent broken bone has focused attention on the issue - England internationals Wayne Rooney, David Beckham, Steven Gerrard, Gary Neville, Ashley Cole and Michael Owen have also suffered the same injury.

Everton and Socceroo midfielder Cahill broke a metatarsal last season simply by landing awkwardly and has had special boots designed to try to avoid it happening again.

Moyes says he is "no expert" but believes modern boots are a contributory factor.

The Everton manager said: "I might get sued by one of the big companies if I say but I think it's a big part of it.

"Players can now pull their boots on like slippers and that did not used to be the case."

Asked about Cahill's new boots, Moyes joked: "I think he has got some boots like the ones we have in our display cabinets with straps and bootlaces and metal toe-caps."

Cahill recently confirmed he has taken steps to avoid the injury.

He told evertonTV: "I don't want to put my body at risk when it is such an innocuous thing that happened - to jump and land.

"I have had new boots made, I have tried different orthotics (foot supports).

"I have kept my weight down and tried to build more muscle and I have been doing different things with the physios and nutritionists as well to make myself stronger for when I get back."