Roger Federer, one of tennis's most celebrated athletes, has shared that the 2009 U.S. Open men's final remains a significant regret in his career. The defeat to Argentina's Juan Martín del Potro, which lasted over four hours, still haunts him, Federer revealed in a recent interview.

"It haunts me more," Federer said, comparing the 2009 loss to his nearly five-hour defeat against Novak Djokovic in the 2019 Wimbledon final. The U.S. Open loss marked the end of his streak of five consecutive men's singles titles at the tournament.

Federer elaborated that he felt he "missed out on so many chances throughout the match," leading to a profound sense of regret. A victory in that 2009 final would have elevated him to six U.S. Open titles, a feat not achieved by a male player in the Open Era since Bill Tilden in 1925, during the amateur era when professional players were not included in the tournament.

Another match Federer cited as a source of regret is his loss to Rafael Nadal in the 2008 Wimbledon final. This match is frequently regarded by tennis fans as one of the greatest in the sport's history. Similar to the 2009 U.S. Open final, Federer entered the 2008 Wimbledon final as the defending five-time champion.

Federer noted that he holds more regrets concerning his matches against Nadal and del Potro than his match against Djokovic, humorously referring to himself as the "king of missing match points."

Recently, Federer received a highly anticipated send-off at Arthur Ashe Stadium. He participated in an exhibition match against his longtime friend and rival, Andy Roddick. The event, attended by a full stadium, celebrated Federer's iconic career. He teamed up with tennis great John McEnroe to face Roddick and Andre Agassi in a doubles exhibition.