SINGAPORE — As Serena Williams enters the twilight of her glorious tennis career, the world may never see another women’s player like her again, says tennis great Monica Seles.

As the 34-year-old American star eases towards retirement, former Yugoslav world number one Seles said it is hard to imagine any player being able to dominate the sport for as long as Williams has.

“I met Serena when she was nine or 10 years old,” Seles, an ambassador for next month’s WTA (Women’s Tennis Association) Finals, said in a phone interview yesterday. “I remember when I played Serena in her first professional tournament in Chicago; I was world No 1 at the time.

“I just remember counting down my days that evening (after the match), and thinking to myself that my days are numbered because I had just played the future world No 1.”

The 42-year-old International Tennis Hall of Famer, who became a naturalised American citizen in 1994, added: “Once Serena retires from the sport, it would leave a void. I’m not sure if we’re gong to see that dominance for a long time.

“It is amazing that Serena is able to do it (in the face of competition from the likes of Martina) Hingis, (Victoria) Azarenka, and her sister Venus. She did it over multiple generations.”

But while Seles hailed Williams as indomitable, she is keeping a close watch on Germany’s Angelique Kerber, who usurped Williams as No 1 last week after winning her first US Open title, and second Grand Slam trophy, in her breakthrough season.

Calling Kerber the best left-handed player since her own time as a player, southpaw Seles said the rise of other players such as Garbine Muguruza and Karolina Pliskova is also good for the women’s game.

“This year just really shows the depth of women’s tennis,” said Seles, a nine-time Grand Slam winner. “Kerber is exciting to see. She is a fellow left-hander, and I think after I was the No 1 left-hander, she is the next one, so we have waited many years for that.

“I always enjoy playing as a leftie, because you have a little bit more craft to your game. And we can see that with (Kerber) on her serve, and on the forehand and how she is tactical on some of the points.

“Also, her mental strength is impressive. Coming into the US Open, knowing what was on the line, and that Serena had to lose for her to get the No 1 ranking, there was extra pressure. But she handled it so well.”

Seles also believes that Kerber, at 28, has age on her side in her quest to stay on top. “It is terrific she has reached all these milestones in her career late on. I think she is more prepared for it mentally, and much more mature than when you reach it at maybe 17 or 18,” said Seles, who was the youngest French Open winner in 1990 at age 16. “So I think she will handle this very well.”

At the season-ending WTA Finals in Singapore, Seles is looking forward to watching Kerber and Williams go head to head.

However, she said Williams will have to listen to her body — the US star missed out on last year’s tournament to rest and recuperate.

“In Singapore, I’m sure Serena would want to prove (something to) everybody out there. She wants to win it and cap off the year,” she said.

“As a former player, I tell you, how you finish the last tournament of the year, it sets the tone for how you view your (past) season, and going into the new season.”