Federer certain decision is final

"I really don't want it to be a funeral," Federer said. "I want it to be really happy and powerful and party mode."

Wearing a blue blazer with the sleeves rolled up to his elbows and a white polo shirt, Federer took questions from various media outlets during the news conference ahead of the team competition founded by his management company.

"I'm nervous going in, because I haven't played in so long," he said. "I hope I can be somewhat competitive."

Federer, who announced last week via social media that he would be retiring after the Laver Cup, said he had struggled to get used to the idea of stepping away from competition.

But it was something he understood he needed to do after running into setbacks in July during his rehabilitation from what was his third surgery on his right knee in about a year and a half.

"You try to go to the next level in training, and I could feel it was getting difficult. ... Then, I guess, I was also getting more tired, because you have to put more effort into it to be able to sort of believe that it was going to turn around. You start getting too pessimistic. Then I also got a scan back, which wasn't what I wanted it to be," Federer explained.

"At some point, you sit down and go, 'OK, we are at an intersection here, at a crossroad, and you have to take a turn. Which way is it?' I was not willing to go into the direction of: 'Let's risk it all.' I'm not ready for that. I always said that was never my goal."

And the hardest part came when he knew he needed to stop.

"You're sad," Federer said, "in the very moment when you realize, 'OK, this is the end.'"