ROGER FEDERER SECRETS OF THE NICEST GUY IN SPORT!

The Swiss tennis great's new documentary Federer: Twelve Final Days tracks his emotional last chapter before retirement

HE'S FRIENDLY WITH RAFA BUT DIDN'T 'RESPECT' NOVAK

Two of the greatest players in tennis for a solid 20 years, Roger and Spanish great, Rafael Nadal, have a long history as on-court rivals. But viewers might be surprised to hear Roger told Rafa 10 days before the big retirement news broke!

He also looks back on his first hesitations of Rafa, admitting, "I liked being at the top alone."

But that didn't stop the pair from becoming friends, and Rafa shares his admiration for Roger in the film when he reflects, "The most important player in my career... is leaving."

Roger also talks about brash Serb player Novak Djokovic, calling him the "party crasher of Rafa and Roger fans" and even admitting he changed his personality because he thought he should be more like him.

"Did I have to grunt more, shout, sweat? I tried, but it was all an act," Roger explains. He confesses he underestimated Novak when they met in 2006, saying, "I think I didn't give Novak the respect he deserved because of his technical flaws."

THE 'PRIVATE' STAR NEVER MEANT TO MAKE A DOCUMENTARY...