Serena Williams has inched closer to making a comeback in tennis as she reportedly registered herself for drug tests. A spokesman for the International Tennis Integrity Agency (ITIA) confirmed the news. The 23-time Grand Slam champion took a step back from the sport in 2022 following her match at the U.S. Open. At the time, she said that she wasn't "retiring," but was "evolving" from it. As of this writing, it is unclear when, or if, she will play again. Her agency has yet to issue a statement. In a statement, ITIA spokesperson Adrian Basset told the Associated Press on Tuesday: "She is on the list and back in the testing pool." Serena Williams opens up about balancing motherhood and tennis: Read more Serena Williams is one of the biggest stars in the sports world. The Associated Press has reported that all athletes who undergo testing are required to offer information on their whereabouts, including their location at non-official events and the timings for when they can give samples. Someone who has been off the list and comes back will have to undergo testing for six months before they can return to the competition. Bassett said he does "not know if this means she is coming back," or if Williams is "just giving herself the option" to return to tennis. "All I can say is she’s back in the pool and therefore subject to whereabouts," Bassett said, per The Athletic. Ahead of competing in the US Open in August 2022, Serena Williams wrote an essay for Vogue, in which she said she "never liked the word retirement" as she announced a hiatus to her almost 27-year-long professional career. "It doesn't feel like a modern word to me," Williams continued in her essay. "I've been thinking of this as a transition, but I want to be sensitive about how I use that word, which means something very specific and important to a community of people. Maybe the best word to describe what I'm up to is evolution." The mother of two said, "I'm here to tell you that I'm evolving away from tennis, toward other things that are important to me."In the years since, Serena Williams has been focusing on her family and kids, including Olympia, 8, and Adira, 2. She shares her daughters with husband Alexis Ohanian. During a recent conversation with People Magazine, the tennis icon admitted that having a night out without her kids is difficult. "I don't like to leave my kids," she remarked. "I have a nighttime routine with them every day." During an April interview for Time magazine, after being named on its list of 100 Most Influential People, she said of motherhood: "I'm a wonderful mom. I think we, as women, don't give ourselves enough credit, but I'm a great mom. I really am. I do everything. I'm freaking the room mom at Olympia's school this year." When asked at the time if she would ever make a comeback to tennis, Serena Williams replied, "I just can't peel myself away from these children. Another reason I had to transition was because I wanted to have more kids. And I look at Adira and I'm like, 'Was it worth it?'I literally thought about it the other day. I was like, 'Yeah, it was definitely worth it." Stay tuned to SoapCentral for more.