Britain’s Chris Froome thinks the Tour de France can work without spectators but does not know how organisers can stop large crowds from attending.
The Tour, originally due to start on 27 June, is now due to begin on 29 August.
No French mass gatherings are allowed before September, but the government has said the Tour could start in August if the first stages were carefully run.
“Would the organisers be able to keep people from coming and gathering in large crowds?" said Froome.
The four-time Tour champion, speaking on an Instagram Live chat with former England cricketer Kevin Pietersen, added: “In theory we can put on the race and it can be broadcast on television.