Team Sky’s road captain, Luke Rowe, could be out for around a year after breaking his leg.
The Welshman was enjoying his brother’s stag party when he broke his tibia and fibula in a rafting accident.
Team Sky immediately sent a doctor out to Prague to assess the 27-year-old and bring him back home.
He has now undertaken what is believed to be the first of many surgeries on his right leg.
Rowe broke a rib on the opening stage of this year’s Tour de France but completed the whole three weeks, helping leader Chris Froome to overall victory.
It is expected this new injury will keep him off his bike for around a year.
He told the BBC: “I knew straight away how serious it was, it was excruciating pain and there are quite a few broken bones. It was a case of trying to get out of the water as quickly as possible and into an ambulance.
“I've broken a fair few bones in my career but this was significantly worse than any of them. It was double the pain - add the pain of a few broken bones together.
“I lifted my leg, but my foot stayed still, it was kind of hanging off, limp. The bone didn't break the skin, but it is pretty scary when you look down and see that when you are on the side of a riverbank.”