England manager Fabio Capello faces an anxious wait after learning that Chelsea defender John Terry has been taken to hospital for a scan on his right foot.
With England's first game in South Africa just over four weeks away, the news comes at a worrying time for the national team boss.
Terry suffered the injury while training for Saturday's FA Cup final at Wembley against Portsmouth.
A statement on Chelsea's official website read:"John Terry has taken a knock in training and has gone to hospital for a precautionary scan on his right foot.
"He left Cobham walking freely in a protective boot and we await the results which are expected on Thursday."
Terry was stripped of the England captaincy earlier in the year following allegations about his private life but had been named in Capello's provisional 30-man World Cup squad on Tuesday.
Fellow centre-halves Rio Ferdinand, Jamie Carragher, Michael Dawson, Ledley King and Matthew Upson were also named in the preliminary squad.