Terry, the cornerstone of the back four for club and country, was injured in training on Wednesday preparing for the weekend FA Cup showpiece against Portsmouth at Wembley where he hopes to lead the west London club to the league and cup double.
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"John Terry has today taken a knock in training and has gone to hospital for a precautionary scan on his right foot," said a statement on the club's website.
"He left Cobham walking freely in a protective boot, and we await the results which are expected on Thursday."
But Terry later calmed fears that he would miss the World Cup next month, telling reporters:
"I took a slight knock in training, but with such an important match on Saturday the right course of action was to put a protective boot on my right foot and have a CT scan.
"The scan has shown there is no break and I am hoping to train tomorrow if not Friday, and of course play in the FA Cup final on Saturday."
The 29-year-old Terry's fitness has been a concern for Chelsea and England at various stages in recent years.
In December 2007 he fractured a metatarsal and was out for 14 games and a repeat of that kind of injury would almost certainly rule him out of next month's tournament in South Africa.
Terry lifted the Premier League trophy on Sunday, Chelsea's first league title since 2006, but his season has been overshadowed by patchy form and newspaper revelations about his private life which cost him the England captaincy.
His fitness for England is key for coach Fabio Capello, however, as there are already question marks over some of the country's other experienced defenders named on Tuesday in the 30-man preliminary squad for the World Cup finals.
Manchester United's Rio Ferdinand, Terry's regular England partner, missed a chunk of the season with back and calf injuries while Tottenham Hotspur's Ledley King has knee problems which mean he cannot train properly.
Midfielder Gareth Barry has an ankle injury while striker Wayne Rooney was troubled by ankle and groin injuries during the final weeks of the season although he is expected to be fit.
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