"My coach told me to save this photo because one day that girl will win a lot of Grand Slams" - Sports journalist Rhiannon Potkey posts picture of herself and Serena Williams from junior tournament

Sports journalist Rhiannon Potkey posted a picture of herself and a young Serena Williams from a junior tournament following the latter's defeat in the third round of the US Open on Friday night.

Tributes have been pouring in for the 40-year-old ever since she announced her retirement from tennis.

Sharing the aforementioned photo on Twitter, Potkey mentioned that she was "pretty disappointed" after her loss to Serena. She added that her coach told her to save the picture as "one day that girl would win a lot of Grand Slams."

Potkey also thanked Serena Williams for "a lifetime of inspiration."

"I was pretty disappointed after this loss. But my coach told me to save this photo because “one day that girl will win a lot of Grand Slams," the caption read. "I am glad I listened. Thank you #Serena for a lifetime of inspiration."

Serena Williams lost to Ajla Tomljanovic in the third round of the US Open

Serena Williams' run at the US Open came to an end

Serena Williams was beaten 7-5, 6-7(4), 6-1 by Ajla Tomljanovic in the third round of the US Open. The match was an exciting contest that lasted three hours and five minutes.

The 40-year-old won two matches at a tournament for the first time this season. She beat Danka Kovinic 6-3, 6-3 and World No. 2 Anett Kontaveit 7-6(4), 2-6, 6-2 in her first couple of rounds in New York.

In her post-match press conference, Serena said that she has not been thinking about returning to action. She admitted that she has come a long way since last year's Wimbledon, when she had to retire in the first round due to injury.

"I don't know. I'm not thinking about that. I always did love Australia, though. But yeah, you know what, I've come a long way since last year at Wimbledon. Just not sure if that was my last moment or not. Making it a different moment I think is much better," the American said.

"Yeah, and it takes a lot of work to get here. Clearly I'm still capable. It takes a lot more than that. I'm ready to, like, be a mom, explore a different version of Serena. Technically in the world I'm still super young, so I want to have a little bit of a life while I'm still walking," she added.

After defeating Serena, Ajla Tomljanovic will be up against Liudmila Samsonova in the fourth round of the US Open.