Stones still has a lot to learn, says Martinez

Roberto Martinez believes John Stones has what it takes to become one of the best centre-halves in Europe but says he still has a lot to learn.

The Belgium boss managed Stones for three years at Everton, during which time he saw him mature into the player Manchester City made England’s most expensive defender when they paid £47.5 million for him in the summer.

"You're talking about one of the best footballing centre-halves in European football, but that's potential," the Spaniard told BBC Radio 5 Live.

"We're very, very quick to judge people and not to understand that he's still a very young man, probably ahead of where he should be."

Stones has come under fire following some below par defensive performances this season, the most recent example coming in his side’s 4-2 defeat at Leicester last weekend, when he was culpable for at least one of the Foxes’ goals.

"You're the last man and when you make a mistake in those areas you are going to get punished. He's someone who needs to learn many aspects of his play," Martinez said.

"The value in the market proves to me he's got the potential to be one of the best centre-halves in Europe but he's not ready yet. His decision-making, he needs to learn certain aspects to make sure he doesn't make mistakes in areas you don't get away with in football."