French Open 2015: Poorly Serena Williams suffering ahead of final

Safarova (right) has lost all eight of her previous meetings with Williams (left)

Serena Williams will have to overcome a bout of flu if she is to win her 20th Grand Slam title at the French Open on Saturday.

The world number one plays Czech 13th seed Lucie Safarova in the Roland Garros final at 14:00 BST.

Williams, 33, struggled in Thursday's semi-final win over Timea Bacsinszsky, and said on Friday: "At this point I just want to get better.

"It's hard to think about the match or winning another Grand Slam title now."

The American did not practise on site or do any pre-final news conference on Friday as she recuperated at her apartment, where she was visited by a doctor.

"I think I have some kind of flu, which makes it tough, because it's just a matter of resting and keeping hydrated - there's not much else I can do," she added.

"I've felt really cold, so I'm just fighting that, trying to sweat it out. A doctor is coming to see me and we'll see if he can do anything else to help, but I don't think there's anything.

"It's just time. I need time and obviously I don't have a lot of it, but it helps that I can be at my apartment and have my family and friends with me."

Williams, a two-time French Open champion, would become just the third player in tennis history - male or female - to win 20 major singles title with a victory on Saturday.

"Being in the final here in Paris means so much to me and it's very upsetting that I feel so lousy right now," she said.

"It's really unfortunate to be like this at the Grand Slam where I feel so at home and really want to win.

"I just have to hope that tomorrow I will be feeling a lot better and able give my best on court."

Safarova, 28, beat Ana Ivanovic in straight sets to reach her first Grand Slam final.

The Czech is a considerable outsider in terms of experience and has lost all eight previous matches against Williams, although they have never met on red clay.

"Serena is number one in the world, a great player," said Safarova. "It's the first time for me, so it's kind of new."

Next week will see two Czech women in the top 10 the first time since 1989, with Petra Kvitova set to rise to second in the new rankings.

"I like all the surfaces, but I think that in the Czech Republic when we grew up, we played a lot through the summer on the clay courts," said Safarova.

"Through the winter we have to go indoors, which are usually very fast surfaces.

"So you kind of train from a small kid to play on anything. I think that forms our game."