Roger Federer said he will play just one doubles match at this weekend's Laver Cup in what would be his last professional match.
The 41-year-old Swiss star announced his impending retirement last week, having failed to recover sufficiently from his most recent knee operation to resume his career.
At a news conference at London's O2 Arena on Wednesday, the 20-time Grand Slam champion said he hoped to be fit enough to compete in one doubles match, probably on Friday night.
"I know my limitations, and this is why I asked Bjorn [Borg, the Europe captain] if it's OK that I play just one doubles," Federer said. "I guess that one would have to be Friday night.
"So here I am, trying to prepare for one last doubles. We'll see how it is. I am nervous, because I haven't played for so long. I hope it goes well."
Playing just one doubles match requires a tweaking of the Laver Cup rules -- a team competition between Europe and the rest of the world in which players usually have to play at least one singles and doubles -- and so Federer will be replaced by Matteo Berrettini for Saturday and Sunday.
Federer said he would love to play the doubles match alongside Rafael Nadal, his longtime rival and friend.
"Of course, no doubt," Federer said. "I think it could be quite a unique situation, if it were to happen. For as long as we battled together, having had always this respect for one another, our families, coaching teams, for us as well to go through a career we both have had, come out the other side and have a nice relationship, is maybe a great message to tennis and beyond.
"For that reason, it would be great, I don't know if it will happen, but it would be great."
As recently as Wimbledon, where he was given a standing ovation at an event to mark the centenary of Centre Court, Federer had hoped he might be able to return. But a scan on the right knee that underwent surgery last summer was not encouraging, leading Federer to announce that he will be stepping away after the Laver Cup, an event he helped to found.
Federer said he was most proud of his longevity and how he had managed to play at the top of the game.
"I was famous for being quite erratic at the beginning of my career," he said. "To become one of the most consistent players ever is quite a shock to me as well. That is a great accomplishment for me personally, that I was able to stay at the top for so long.
"There are so many things I will miss; the fans are at the center of everything. I will miss that, every interaction on the court and off the court."