For the time being, Serena Williams will remain the world's No. 1 player in women's tennis. Angelique Kerber fell in the round of sixteen in Stuttgart despite being the defending champion there. As a result, Kerber will not get back up to No. 1 in the world with the May 1st rankings. She fell to France's Kristina Mladenovic in Stuttgart recently on clay 6-2, 7-5.

Serena Williams can't stay No. 1

It is just a matter of time before Williams loses Top Spot as she is on maternity leave and will be for quite some time. That makes it impossible for her to defend ranking points and the other players will inevitably gain on her and overtake her.

With Kerber slumping for ages, it looks like Karolina Pliskova is the one that will likely get the No. 1 ranking. She is still in the Stuttgart draw as she advanced to the quarterfinals with a win over Coco Vandeweghe. Pliskova will not be able to get to No. 1 with a title in Stuttgart, however the goal is possible before the end of the clay-court season for sure. When it comes to live rankings heading into the weekend, Pliskova is within 1000 points of the pace set by Williams.

Simona Halep, who beat Barbora Strycova in the round of sixteen in Stuttgart, is another player that is in the mix for top spot. The Romanian, currently ranked 5th in the world but will be 4th on Monday, certainly has a history of clay court success.

Last year she won both Bucharest and Madrid and a few years ago she made the French Open final. In terms of room for growth in the near future, the Stuttgart draw offers opportunity for her. She'll have a title to defend in Madrid soon, but she didn't do well in either Rome or Paris for her standards. Accordingly, she is a player that has a good chance to turn a net gain for ranking points in the weeks ahead.

Maria Sharapova long-term No. 1 potential

With Kerber out of the Stuttgart draw, the top half of the tournament is now Mladenovic and Maria Sharapova. The latter defeated Anett Kontaveit in the tournament's quarterfinals on Friday and is into the semifinals. However, at this point Mladenovic is too far back from the top spot to be considered a contender for No.

1 even with Serena Williams destined to fall from it soon. Russia's Sharapova certainly might re-enter the mix, but that would only be in the long term, as she just recently started getting ranking points again after her lengthy suspension. With Kerber slumping, the race for the top spot looks like a battle between Pliskova and Halep at this point in the 2017 WTA season.