With more 130 caps and a wealth of tournament experience between them, England's previous and current captains should be certain starters for the finals in South Africa in June.
However, if coach Fabio Capello was looking at this season's domestic form alone, both would struggle to make the team.
Terry's form has dipped since newspaper revelations in January that he had an extra-marital affair with the former partner of England team mate Wayne Bridge.
Stripped of the England captaincy as a result, Terry continued as Chelsea skipper but even fans of the Stamford Bridge club would acknowledge 'JT' has been badly off the pace at times in recent weeks.
On Saturday he gave an error-strewn display and was sent off in the second half after two clumsy challenges as the Premier League leaders lost 2-1 at Tottenham Hotspur.
Terry suffered in comparison with Tottenham's improving centre-back Michael Dawson, who could yet make a late dash into the World Cup squad, and Carlo Ancelotti's words of support after the game had a hollow ring.
"People are looking too much at John Terry's performances," said the Chelsea coach. "He is doing very well.
"He did a fantastic season," added the Italian. "Maybe sometimes he had some problems and didn't play so well, maybe against Tottenham he didn't play too well, but he has been absolutely fantastic."
MEDIOCRE DEFENDING
If "absolutely fantastic" means mis-judging simple long balls, cumbersome turns, ill-advised handballs and mediocre defending, then Ancelotti is spot on in his analysis.
Terry was embarrassed by Everton's Louis Saha in Chelsea's 2-1 defeat at Goodison Park in February and the England centre-half said he was disappointed with his display.
Last month, though, he declared himself generally pleased with his form through the season.
Terry delivered his usual heart-on-the-sleeve show for England in a friendly against Egypt, showing strong character to come through so soon after losing the captaincy, but it will need more than bravery in the tackle and clenched-fist exhortations to keep the world's leading attackers at bay.
Ferdinand has also had his troubles this season.
A succession of injuries, including a long-running back problem, have limited him to short bursts of action for Manchester United followed by spells in the treatment room.
Long odds would be available on the 31-year-old getting through seven games in a month should England go all the way to the final in his fourth World Cup.
Ferdinand is never short of confidence but for it to be justified he needs to be playing regularly, to ensure his timing, positioning and anticipation are 100 percent.
Capello's back-ups - Matthew Upson of West Ham United, Manchester City's Joleon Lescott and Wes Brown of Manchester United - are steady league performers without carrying the aura of potential World Cup winners.
England hopefuls Da
