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Cavendish is not guaranteed his place but Wiggins told BBC Radio 5 live he is "the right man to ride the omnium".
Wiggins added: "I think Mark will be in Rio and I want him there.
"The Olympics is the one that it's really about for him. Once he gets given the green light for that, his performance will go up again because he's got nothing to lose."
Cavendish intends to combine his dream of winning Olympic gold for the first time with his glittering career on the road.
Watch the full interview with Wiggins
Wiggins: "I'd love to play in a rugby match"
In the build-up to Rio, the 30-year-old from the Isle of Man intends to ride in the Tour de France again with the hope of adding to his 26 stage wins in the race.
Wiggins, who won the Tour de France in 2012 and is also an Olympic champion on both the road and the track, says Cavendish will make sure he does what is right to achieve success in Brazil.
"Mark is a special character and he needs to be given freedom to do it his way," said Wiggins, who partnered Cavendish to madison gold at the Track World Championships last month.
"He'll do what he thinks is best for him and I think he'll think that riding the Tour de France for his fitness will be better for him for the omnium."
Sir Bradley Wiggins says Mark Cavendish will make Great Britain's track team for the Olympic Games in August.