Serena Williams passed another stage on the path to a possible comeback to professional tennis, being listed Monday by the sport’s drug testing organization as eligible to return to competition on Feb. 22.

That is six months after the 23-time Grand Slam singles champion initially registered with the International Tennis Integrity Agency. Williams, 44, was listed on the ITIA website’s reinstatement page Monday.

What was not immediately known was when, where or even whether Williams actually will play again.

When it was revealed last year that Williams had signed up with ITIA to return to the drug testing pool, she wrote on social media: “Omg yall I’m NOT coming back. This wildfire is crazy.”

Her agent did not immediately return a request for comment Monday. Neither did a spokesperson for the WTA Tour.

Williams, one of the greats of the game, has not competed since the 2022 US Open. At the time, Williams said she didn’t want to use the word “retiring” and instead declared that she was “evolving” away from tennis.

Athletes returning to testing need to provide information on their whereabouts — details on their location when they are not at an official event and times when they are available to give samples. Someone who retires while they are on the list and later comes back needs to be available for testing for six months before they are allowed to return to competition.

Last year, when word emerged that Williams had made an initial move required for a return, U.S. Tennis Association spokesman Brendan McIntyre said: “If Serena decides to return and compete at the professional level, together with her fans, we will enthusiastically welcome the return of one of the greatest champions in the history of our sport.”

Williams’ older sister, Venus, returned to competition in July at age 45 after nearly 1½ years away from the tour; she never had announced her retirement. At the US Open, Venus Williams became the oldest player to play singles at the American Grand Slam tournament since 1981.

When Venus, a seven-time major singles champion, came back at the DC Open, she spoke about wishing Serena would join her back on tour. They claimed 14 Grand Slam doubles titles as a pair.

“I keep saying to my team: The only thing that would make this better is if she was here. Like, we always did everything together, so of course I miss her,” Venus Williams said at the time when asked about a video on social media that showed Serena swinging a racket. “But if she comes back, I’m sure she’ll let y’all know.”