And now she will go into her first Grand Slam match in 497 days without a single warm-up match on clay with all of her competitive tennis in 2018 having come on hard courts.
Maria Sharapova won the French Open in 2012 and 2014 and according to Chris Evert, the Russian can triumph again in Paris this year.
Should she get through the first couple of rounds, Serena appears to have been handed a good draw, although may have a potential last-16 clash with Kristyna Pliskova's sister and sixth seed Karolina, who reached the semi-finals past year.
This will be her first Grand Slam since her victory at the 2017 Australian Open, after which she stepped off the tour to give birth to her daughter in September.
After the news broke that former number 1 Serena Williams would have to compete in the French Open but as an unseeded challenger, many were infuriated by the decision calling it unjust and unfair to women.
"She played against her twice, which is good for me", Kristyna said of Karolina.
Play has been interrupted at the French Open because of rain.
Starbucks Closing More Than 8,000 Stores Tuesday Afternoon For Anti-Bias Training
They were sitting in the store without ordering anything as they waited for a friend when the cops were called. Starbucks has put information about hours of its stores Tuesday on its website and mobile app.
In Rome last week, Sharapova spoke up in support of her long-time rival.
But the elegant and powerful Muguruza is not anxious. "We didn't play. She played more some practices so she told me a little bit more about Barbora today", she said of Barbora Krejcikova, whom she beat 7-6 6-4 in the first round on Monday.
After beating Serena Williams in the 2016 final, Muguruza's title defense was ended in the fourth round past year.
Also in the women's first round, 2016 victor Garbine Muguruza plays another former French Open champion, Russia's Svetlana Kuznetsova, who won in 2009.
"Of course being the defending champion for the first time, it adds a lot of pressure and expectation, and for sure this year you think different", Muguruza said.
"I don't really think so", said Kvitova who was off the tour for six months previous year after suffering knife wounds fighting off a burglar at her home in the Czech Republic.
The French Open draw will be made on Thursday, with the tournament starting on Sunday.