London - Team Sky's Luke Rowe is facing a long spell on the sidelines after breaking his leg while white-water rafting on his brother's stag party, his team have announced.
Sky said Rowe, 27, had fractured his tibia and fibula and was recovering from surgery at his home in Cardiff.
He was Sky's road captain at this year's Tour de France and overcame a first-stage fall to help Chris Froome win the race for the fourth time.
"On the first morning we went white-water rafting. I jumped down into the water, but landed in a shallow section on my right leg," Rowe told the Team Sky website.
"I knew straight away that it was a bad one. It's been a big shock and I know I've got a long period of recovery ahead."
Rowe's brother, Matt, is due to marry Dani King, who won a gold medal in the team pursuit at the London 2012 Olympics.