Beckham stressed that he would only take up the offer from Capello and his number two Franco Baldini, if he had recovered sufficiently from the injury he suffered in March.
"Everyone knows with Fabio Capello and his staff you are there for a reason and that is to help the team and to be successful," he added.
"I am hoping to travel with the team but obviously we'll have to see how my therapy goes."
Two days after Beckham sustained his injury, Capello announced his intention to ask the midfielder to travel to South Africa as part of his staff.
WORLD CUP COUNTDOWN
17 May: 30-man squad travel to training camp in Austria
24 May: England v Mexico at Wembley
30 May: Japan v England at UPC-Arena, Graz, Austria
1 June: Deadline to name 23-man squad
2 June: Squad travel to World Cup base in Phokeng
The role would be Beckham's first in coaching, although he is a vice-president of England's bid to host the World Cup in 2018.
He also played an important ambassadorial role in London's successful 2012 Olympic bid.
England begin their World Cup campaign against the USA on 12 June after friendlies against Mexico and Japan on 24 and 30 May respectively.
A provisional 30-man group will fly out to Austria for a training camp on Monday, before Capello selects his final 23-strong squad for the tournament by 1 June.
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