Bradley Wiggins believes teammate Mark Cavendish has to leave Team Sky to advance his career, the Tour de France winner and Olympic time trial champion said. "On a personal level I have enjoyed riding with him, but I understand why he would probably have to leave," Wiggins said. "I love seeing him win as much as anyone else and to see Mark back out on the Tour [de France] winning six, seven or eight different stages and challenging for the green jersey, he probably has to go." Cavendish, 27, was part of the team who helped Wiggins become the first Briton to win the Tour, but the Manxman enjoyed just three stage wins as team orders took priority. Cavendish still has more than two years left on his Sky deal.