Charlton remains the Three Lions record scorer with 49 goals and he was also a pivotal member of the 1966 World Cup winning team every other England side is compared to.
"People wonder whether we will ever win it again. I worry about that as well," Charlton said at the Soccerex conference in Manchester. "When I am asked to give my opinion, I always say yes (we can win the World Cup) but it is a fool's errand."
He added: "You need good players. But if all the spaces at English clubs are taken by foreign players, you have no chance."
With England presently labouring in their attempt to reach next summer's World Cup in Brazil, Charlton's assessment seems fairly astute.
"It is hard to think we could win a World Cup when you see the quality of the other teams," he said.
"Spain would have to be my favourites for Brazil, plus Germany, because they have some good players emerging.
"I want to see some English players emerge."