John Stones: Manchester City defender 'ahead of where he should be'

Roberto Martinez says England's John Stones can
become one of Europe's best defenders - if given
time to learn.
The 22-year-old has been criticised for making
costly mistakes since a £47m move to Manchester
City from Everton.
But his former Everton manager Martinez - now
boss at Belgium - says he should not be under so
much pressure.
"You're talking about one of the best footballing
centre-halves in European football - but that's
potential," the Spaniard said.
"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."
LISTEN: Martinez on Stones and Barkley
He added young centre-halves were "rare" - and
so was the number of managers willing to play
youngsters in such an important position.
"You're the last man and when you make a mistake
in those areas you are going to get punished,"
Martinez explained.
In last week's Premier League game against
Leicester City, Stones played a back-pass to Foxes
striker Jamie Vardy, who rounded the goalkeeper
and scored.
The defender was then left out of Manchester City's
starting line-up for their midweek win against
Watford.
"He's someone who needs to learn many aspects
of his play," Martinez told BBC Radio 5 live.
"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."
Martinez also expects another of his former Everton
players, midfielder Ross Barkley, to come good.
The 23-year-old has been in and out of the Everton
side under new boss Ronald Koeman but Martinez
said: "The first time I took my first session at
Everton I saw a player that could do things I've very
rarely seen players do. Ross Barkley has a special
natural talent and I'm sure he'll come through and
show his real potential."
Since taking over the Belgium national team in
August, Martinez has guided the Red Devils to four
wins from four 2018 World Cup qualifying matches -
scoring 21 goals and conceding just one in the
process.
He was appointed only three months after getting
sacked by Everton, where he had spent three
years.
Martinez led Everton to fifth in the Premier League
in his first season and Europa League qualification.
Last season the Merseysiders appeared in the
semi-finals of both domestic cup competitions - but
he lost his job with the Toffees lying mid-table in
the Premier League with five home wins all season.
Martinez says he accepts results were not good
enough to keep him in a job given the short-term
demands of the modern game, but added: "I will
always treasure my memories as an Everton
manager - reaching the Europa League, getting 72
points, and then last campaign we were so so close
to getting to the finals of both domestic cups.
"I still get satisfaction with our long-term project
that we had in hand, seeing players that we
invested in heavily, giving them big roles like the
level of investment in young players like John
Stones, Ross Barkley and Romelu Lukaku, that they
have taken the football club to a different level