Fabio Capello is thinking about playing with three central defenders during the World Cup, BBC Sport understands.
The England boss is considering a move to 3-5-2 from 4-4-2 if Manchester City's Gareth Barry is forced out of the tournament by his ankle injury.
Capello has never played with three at the back since taking charge of the national squad in 2008.
England played a similar system under Steve McClaren in 2006, when they went down 2-0 away to Croatia.
"England's World Cup starts four weeks on Saturday and there is a chance they could start with three central defenders against the USA in Rustenburg [on 12 June]," reported BBC Radio 5 live's Ian Dennis.
606: DEBATE
To my way of thinking you need to select your preferred system and the players best suited to deliver it
billyall
"Capello has never played such a system with wing-backs in his time as manager, but I understand he will consider a change in formation if Barry doesn't recover from his injury.
"Capello spoke of his plans to members of England's '66 World Cup-winning side, who were inducted into football's Hall of Fame on Thursday.
"England played with three at the back during the ill-fated Euro 2008 qualifiers, but at least Capello has weeks rather than days to work on the system, which worked well during Italia '90."
A switch in formation would be a major change for the Italian, who has demonstrated his preference for 4-4-2 throughout his coaching career.
Four years ago England's deployment of a 3-5-2 formation ended disastrously against Croatia.
World Cup guide - England
Eduardo headed Croatia ahead in Zagreb, then Paul Robinson's air-kick after the ball bobbled on an uneven surface resulted in an own-goal for Gary Neville, with the Croats going on to win 2-0.
Capello sprang some surprises in his provisional 30-man squad for South Africa on Wednesday, calling up Liverpool defender Jamie Carragher who retired from international duty in 2007.
Fellow central defenders Rio Ferdinand and Ledley King have both proved vulnerable to injury in recent years, while some critics have suggested former England captain John Terry has not been always been at his best this season.
Barry played in eight of England's 10 World Cup qualifiers, and has won 20 of his 36 international caps under Capello. The midfielder was named in the provisional squad and will have a fitness check on 24 May.
Manchester City said on 7 May that his ankle injury would rule him out for four weeks.
The England boss is considering a move to 3-5-2 from 4-4-2 if Manchester City's Gareth Barry is forced out of the tournament by his ankle injury.
Capello has never played with three at the back since taking charge of the national squad in 2008.
England played a similar system under Steve McClaren in 2006, when they went down 2-0 away to Croatia.
"England's World Cup starts four weeks on Saturday and there is a chance they could start with three central defenders against the USA in Rustenburg [on 12 June]," reported BBC Radio 5 live's Ian Dennis.
606: DEBATE
To my way of thinking you need to select your preferred system and the players best suited to deliver it
billyall
"Capello has never played such a system with wing-backs in his time as manager, but I understand he will consider a change in formation if Barry doesn't recover from his injury.
"Capello spoke of his plans to members of England's '66 World Cup-winning side, who were inducted into football's Hall of Fame on Thursday.
"England played with three at the back during the ill-fated Euro 2008 qualifiers, but at least Capello has weeks rather than days to work on the system, which worked well during Italia '90."
A switch in formation would be a major change for the Italian, who has demonstrated his preference for 4-4-2 throughout his coaching career.
Four years ago England's deployment of a 3-5-2 formation ended disastrously against Croatia.
World Cup guide - England
Eduardo headed Croatia ahead in Zagreb, then Paul Robinson's air-kick after the ball bobbled on an uneven surface resulted in an own-goal for Gary Neville, with the Croats going on to win 2-0.
Capello sprang some surprises in his provisional 30-man squad for South Africa on Wednesday, calling up Liverpool defender Jamie Carragher who retired from international duty in 2007.
Fellow central defenders Rio Ferdinand and Ledley King have both proved vulnerable to injury in recent years, while some critics have suggested former England captain John Terry has not been always been at his best this season.
Barry played in eight of England's 10 World Cup qualifiers, and has won 20 of his 36 international caps under Capello. The midfielder was named in the provisional squad and will have a fitness check on 24 May.
Manchester City said on 7 May that his ankle injury would rule him out for four weeks.