Naomi Osaka's fluctuating form before the French Open is a sign that the newest star in women's tennis is struggling with the pressure of being number one, Spanish tennis great Arantxa Sanchez Vicario said. Osaka, 21, took the tennis world by storm when she beat Serena Williams in the US Open final last September and claimed a second successive Grand Slam title at this year's Australian Open to become the first Asian player to top the singles rankings. She is also the first woman to win a second slam immediately after her first since Jennifer Capriati in 2001 but her meteoric rise has been followed by a distinct dip ahead of Roland Garros. She pulled out of the Italian Open on Friday with a hand injury, casting doubt on her ability to start in Paris. "It happens to everyone," three-times French Open champion Sanchez Vicario told reporters in India shortly before Osaka's latest withdrawal. "When you reach number one, the pressure is double and everyone wants to beat you. "It's hard to put it all together but once you're ready for it... it's a different story." Osaka's success has made her one of the most marketable players in the game — her switch from Adidas to Nike last month made headlines around the world and she even has a Barbie doll in her likeness. However, she has recently struggled with injuries and poor form and raised eyebrows by firing her coach Sascha Bajin less than a month after her Melbourne triumph in January. GREAT EXPECTATIONS Sanchez Vicario, who is in Bengaluru to promote the TCS World 10K run, knows a thing or two about the pitfalls of fame and the 47-year-old empathizes with the balancing act that Osaka is having to carry out. She was 17 when she stunned Steffi Graf in the 1989 Roland Garros final to win the first of her four major singles titles, but unlike Osaka, had to wait five years for her second. "I had nothing to lose against Steffi but after that, they expected me to win everything and be number one straightaway. To handle that when you're young isn't easy," she said. Osaka withdrew from the Qatar Open with a back problem in February and was beaten by Kristina Mladenovic in her first match back in Dubai a few weeks later. She lost to Switzerland's Belinda Bencic in the last-16 at Indian Wells in March and the Madrid Open quarter-finals earlier this month. A third-round defeat by Taiwan's Hsieh Su-wei in the Miami Open was followed by her withdrawal from the Stuttgart semi-finals with an abdominal injury. Despite the recent setbacks, Sanchez Vicario was confident that Osaka will be soon back to her free-flowing best. "If she's free of injury then definitely she's the player to watch after the domination of Serena Williams. If she's healthy, (Osaka is) one of the title contenders," Sanchez Vicario said. — Reuters