The tennis great took to social media to share a valuable piece of advice on expectations.
Frances Tiafoe sealed the title for Team World with victory over Stefanos Tsitsipas.
Federer, who won 20 major singles titles, played Nadal 40 times in one of the most compelling rivalries across any sport.
In front of a 17,500 sell-out crowd in London, 20-time Grand Slam champion Federer returned from more than a year away for a last dance in tandem with his great rival on a gripping and memorable finale by the Thames.
The iconic duo will join forces at the Laver Cup on Friday.
The iconic player made his announcement via a lengthy social media post.
The three-day team event pits six of Europe's top players against six from the rest of the world.
Team Europe's Nadal was also scheduled to take on Team World's Nick Kyrgios in his singles clash.
Rafael Nadal and doubles partner Stefanos Tsitsipas were beaten by Nick Kyrgios and Jack Sock in the final match of the day as Team World cut down Team Europe's lead to 7-5.