Fabio Capello is giving serious thought to installing Joe Hart as his number one goalkeeper at the 2010 FIFA World Cup South Africa™ - even though he has just 45 minutes' worth of international experience behind him.

Hart will win his second cap in tonight's friendly with Mexico at Wembley, confirmation of the vast strides he has made this term following an excellent season on loan at Birmingham. Even so, it is hard to imagine Hart being in line to oust former regular number one David James, or Robert Green, who has started seven out of England's last nine games and is favourite to be named in Capello's starting line-up for the Group C opener against the United States in Rustenburg on 12 June.

Yet Capello will not discount the idea, having found himself in the rather strange position of not knowing who his best goalkeeper is less than three weeks before he puts his reputation on the line. "I have confidence in Joe Hart," said Capello. "He will play 45 minutes against Mexico because it is important for him to play at Wembley.

"He did play in Trinidad and Tobago but the pressure at Wembley is really big. Hart has played a lot of games this season and has improved a lot. It is very equal between the keepers and they are all starting in the same position."

It is impossible to believe that Capello is unsure about the pecking order, and more will be known once the Italian announces his starting line-up for the final friendly, against Japan in Graz on 30 May. Yet in the past week Capello has seen German and French plans thrown into turmoil because of injuries to Michael Ballack and Lassana Diarra and is therefore wary of committing himself too early.

"I prefer to decide at the last minute," he said. "It is really dangerous to decide too early. In my mind, I always prefer to decide the first XI the day before but I don't announce the team until two hours before."

If there is anyone who should have noted Blackpool's staggering rise from Championship obscurity to Premier League status with particular interest it is Adam Johnson. After all, the winger was playing in the Championship for Middlesbrough until January, when he was plucked away by Manchester City on the recommendation of Brian Marwood and then, in Capello's own words, become the most improved English qualified player of the season.

Johnson ripped Jamie Carragher apart in training often enough this week to suggest he can cause havoc in South Africa as, although his inexperience makes him more likely to be of use during the UEFA EURO 2012 qualifiers in the autumn, Capello might still find a role for him as he tinkers with the basic 4-4-2 formation he prefers to use.

I want flexibility in my players. My style with England has always been 4-4-2, or 4-3-1-2 with Steven Gerrard free behind the two forwards.

England manager Fabio Capello

"I want flexibility in my players," he said. "My style with England has always been 4-4-2, or 4-3-1-2 with Steven Gerrard free behind the two forwards. But with Roma I played with three centre-backs and we have been practising that."

"I have to study the opponents but we can play different styles and we have to prepare for everything. You never know when you will get an injury, or find yourself 10 against 11. Sometimes I have changed the style four or five times in a game, so it is important that we have a lot of options.

More will become clearer once Gareth Barry has the results of his scan on the ankle injury that threatens his place in the tournament. If Barry is going to be fit for the United States game, he will travel. If not, Capello has some deep thinking to do, having committed himself to giving the Manchester City midfielder as much time as possible to recover and failed in his attempt to lure Paul Scholes out of international retirement.

Mind you, the two days between the Japan game and Capello submitting his 23-man squad to FIFA on 1 June will not be easy anyway as the Italian regards ditching the six, or seven - depending on Barry's fitness - from the 30 currently on duty, as his toughest job.

"The hardest decision is to decide which players will go," he said. "I have spoken with the players and said that to be in the 30-man squad is really important. But they also have to understand that I must choose. I need to wait and see what happens after the last game because there might be injuries. Then I will ring them."