Serena Williams Congratulates Roger Federer on Retirement: 'Always Looked Up to You'

Roger Federer announced his intentions to retire after his next competition, becoming the second tennis legend to call it a career within the past few weeks.

Serena Williams, who retired after losing in the third round of the U.S. Open, offered kind words to Federer in a touching Instagram post.

"I have always looked up to you and admired you," Williams wrote. "Our paths were always so similar, so much the same. You inspired countless millions and millions of people - including me - and we will never forget."

Williams continued: "I applaud you and look forward to all that you do in the future. Welcome to the retirement club. And thank you for being you."

Unlike Williams, the Swiss superstar won't be ending his career at a Grand Slam. Federer, who turned 41 last month, announced that he will retire after participating in the Laver Cup, which takes place Sept. 23 to Sept. 25 in London. He cited injuries as the reason for his retirement.

"As many of you know, the past three years have presented me with challenges in the form of injuries and surgeries," Federer said. "I've worked hard to return to full competitive form. But I also know my body's capacities and limits, and its message to me lately has been clear."

Undoubtedly one of the greatest male tennis players of all time, Federer will finish his career with 20 Grand Slam singles titles, the third-most behind Rafael Nadal (22) and Novak Djokovic (21). Williams holds the all-time Open Era record with 23 major singles titles.

The retirements of both Federer and Williams represent the beginning of tennis' shift to the next generation of stars. The U.S. Open was won by two players early in their careers: 21-year-old Iga Świątek, who won her third career major, and 19-year-old Carlos Alcaraz, who won his first.