That opens up the possibility that the Swiss star is teaming up with Nadal, 18 years after they first met on the ATP Tour in Miami.
The pair have met 40 times over the course of their careers – including nine Grand Slam finals – and also played together at the 2017 Laver Cup.
“As long as we competed together, we’ve always had this respect for each other – our families, our coaching teams – we always got along really well,” Federer told reporters when asked about the opportunity to play alongside the Spaniard.
“To go through the careers we’ve both had, to come out on the other side and have a nice relationship, I think, maybe a great message too — to not only play tennis, but also play sports.” .
“For that reason I think it would be great. I don’t know if it will happen, but I think it could be a special moment of course.”
Federer said he needed to get permission from Team Europe captain Björn Borg and the tournament organizers to play in just one doubles at the Laver Cup this week.
The competition sees teams from Europe and the rest of the world compete in nine singles and three doubles matches over three days.
“Here I am trying to prepare for a final double,” said Federer. “We’ll see who it is with. I’m nervous to go in because I haven’t played in so long. I hope I can be somewhat competitive.”
The 41-year-old has undergone multiple knee surgeries in recent years, most recently losing to Hubert Hurkacz in the quarter-finals of Wimbledon last year.
He said he still plans to return to the sport next year, two months ago before making the decision to retire.
“I just wanted to let the fans know that I won’t be a ghost,” Federer said when asked how he would remain involved in tennis after retirement.
“I feel like tennis has given me too much, I’ve been in the game for too long, I’ve fallen in love with too many things.
“I like seeing people again and that’s what I wanted to let the fans know – that you will see me again … What it could be, in what capacity, I don’t know. I have yet to think about one bit over and give myself time.”
Among the many accolades of his tennis career, Federer won 103 singles titles and 20 grand slam titles – an overall second only to Nadal (22) and Novak Djokovic (21) in the all-time men’s list.
He became the world’s oldest ever No. 1 at the age of 36 and also topped the world rankings for a record 237 consecutive weeks between 2004 and 2008.