England captain Martin Johnson has been ruled out of England's crucial Six Nations clash against France after suffering a head injury in training.

Johnson was taking part in his first full training session with his club Leicester when he suffered a blow to the head.

Leicester's director of rugby Dean Richards says there is no way Johnson will be fit for the match in Paris on February 19.

"He took a knock in training and was concussed. It will keep him out for two to three weeks," said Richards.

The news is big blow to Johnson, who has not played competitive rugby since the beginning of December because of an Achilles injury and missed England's opening Six Nations clash against Ireland.

Richards says Johnson only decided to train on Tuesday night because his foot injury had been clearing up.

"It was touch and go whether he played this week and he was going to test it in training although maybe it is better he is out now as knowing Martin he would have tried to rush back."

Scrum-half Matt Dawson captained England for the opening match and he will be handed the skipper's armband again.

With Wales and Scotland both having lost their opening matches, commentators say the Paris clash could decide this season's championship.