England defender Matthew Upson suffered a head injury during training in Austria on Wednesday.
Fabio Capello's squad are currently going through their paces on the continent and training in high altitude conditions in Irdning, as the players look to make the final 23-man party named on 1st June.
West Ham centre-back Upson clashed heads with a team-mate and suffered a bad cut which leaked blood.
He lay motionless for a second as Capello and goalkeeping coach Ray Clemence looked on, but he soon got to his feet again and was able to continue training.
Upson is one of those players who is not certain of a place on the plane to South Africa, with central defence one of Capello's problem areas.
With John Terry and Rio Ferdinand expected to earn a place in the England starting XI, it remains to be seen who out of Upson, Jamie Carragher, Ledley King and Michael Dawson will make it to the World Cup.