Roger Federer said Wednesday he wants to team up with long-time rival Rafael Nadal for the final match of his career at the Laver Cup in London.

The 20-time Grand Slam winner announced last week he intended to retire after the tournament at London's 02 arena, which starts on Friday.

Federer, whose last competitive match was a loss to Hubert Hurkacz in last year's Wimbledon quarter-finals, has been struggling with a knee problem.

He will play in the doubles on Friday evening but will not play a singles match in London.

The Swiss does not yet know whether he will be able to team up with Nadal but said that would be the dream scenario.

"Of course, no doubt," he told a packed press conference. "I think it would be quite a unique situation if it were to happen.

"For as long as we battled together, there was always this respect for one another -- our families, our coaching teams, we always got along really well.

"For us as well to go through the careers we've both had and come out the other side and be able to have a nice relationship, I think is maybe a great message as well to not just tennis and sports but maybe even beyond.

"For that reason it would be great. I don't know if it's going to happen but it would be a special occasion."

Nadal, who holds the record for Grand Slam titles with 22, Novak Djokovic, who has won 21, and two-time Wimbledon champion Andy Murray are all part of Team Europe.

Their opponents, Team World, include Taylor Fritz, Felix Auger-Aliassime and Diego Schwartzman.

Federer said he was happy to retire from playing at the age of 41 but admitted it was a "bittersweet decision".

"You always want to play forever," he said. "I love being out on the court, I love playing against the guys, travelling.... I love my career from every angle."