Jonas Armstrong, who plays Robin, fractured a metatarsal, reportedly while performing a staged fight on set, The Mail on Sunday reported.
The show could take a huge hit in costs because of the injury, the newspaper said. Tiger Aspect, which makes the program, reportedly hopes insurers will cover loss.
"We can confirm that Jonas has fractured a fifth metatarsal in his foot. He is currently back in the (United Kingdom) and is seeing a specialist and resting," said a spokesman for the BBC. "The film schedule has been moved around and Robin Hood will go ahead as planned in the autumn."
Technical crews have been told filming may be stopped, and they may not be paid if the delay continues, the newspaper said.
An insider says there may be some doubt about whether Armstrong, who is not a stunt specialist, should have been taking part in the fight scene.
The BBC spokesman denied that the accident happen while Armstrong was filming a fight scene.