Hyderabad: A day after she entered the world top 100 rankings moving from 134 to 99, Sania Mirza says she is prepared for the challenge to stay in the top 100. Sania is now the first Indian to be ranked among the top 100 women tennis players in the world. "Maybe instead of playing Serena once in a Grand Slam, I will be probably playing her 4-5 times in a year. So obviously it is going to be tougher to face Serena everytime you go on to the court," said Sania Mirza, World Number 99 player.Tough timesWhat this would mean is Sania's presence at more high-profile tournaments. While Sania has shown that she has it in her to belong to the top 100 club, the climb from 99 to 50 will be much more tough. Sania has set a target of breaking into the top 50 by the end of the year."Once you keep playing better players, it is a lot physically demanding. They are going to make you run around, they are going to hit that extra ball. She really needs to focus on her physical aspect. She needs to take care of her injuries and work on her endurance and power," said Narendranath, Sania's former coach.Sania hopes to get a wild card for the Dubai Open which starts February 28. If she does play there, it will be a good reality check because the cut-off rank at the Dubai Open is 60.