Novak Djokovic dropped a bombshell about fellow tennis icon Serena Williams after advancing to the second round of the US Open. It's been three years since Williams ended her career at her home Grand Slam tournament, and Djokovic wants to see her back on the circuit.

There has been plenty of speculation over whether Williams could make a surprise return and team up with her sister, Venus. One of their old coaches even believes they'll play together in New York this week. And Djokovic has thrown another spanner in the works, telling the 23-time Grand Slam champion to make a comeback in 2026.

Since ending her career in the third round of the US Open three years ago, when she stunned world No. 2 Anett Kontaveit before losing to Ajla Tomljanovic, Williams has made limited appearances at tennis tournaments.

She came to last year's US Open, and over the weekend, she made a surprise appearance in Newport, Rhode Island, to induct her old rival, Maria Sharapova, into the International Tennis Hall of Fame.

"It was a beautiful moment," Djokovic said after watching Williams introduce Sharapova with a heartfelt speech.

"It was surprising, but very nice gesture from Serena to be there for Maria. They had some really intense rivalries and incredible matches over the years."

But he wants to see more of the former world No. 1 on the tennis scene again, even suggesting that Williams hadn't truly retired from the sport.

Djokovic added: "Of course, seeing Serena in any shape or form around tennis is great. You know, we miss her. She still hasn't officially retired.

"So I invite her, I challenge her. Because she's such a great competitor, when somebody challenges her, she never refuses. So I challenge Serena, come back on the tour next year."

The world No. 7 could well get his wish. Williams has shared snippets of herself on the practice court in recent months.

Her older sister, Venus, recently returned from a 16-month hiatus at the WTA 500 in Washington. Aged 45, reached the second round in both the singles and doubles draws, becoming the oldest player to win a WTA Tour match since 2004.

Ahead of the US Open, their former coach Rick Macci suggested the sisters could team up in doubles this week. "Asked if Serena will play doubles with Vee at the OPEN," he tweeted.

"My gut is probably because at the end of the day Serena can still play even though she has been away. Her serve is still one of the best on the planet and when she competes her mindset is like granite."

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