World No. 1 tennis player Serena Williams, who holds 21 major titles, may soon add another superlative to her resume: world's highest-paid female athlete.
The likely shift comes as Maria Sharapova, the World No. 7, announced Monday that she failed a drug test at the Australian Open in January. As a result, many of the big brands that have endorsement deals with the Russian 5-time major champion—including Nike, Porsche, and TAG Heuer—have suspended their arrangements.
Sharapova said she had been taking a drug, called meldonium, since 2006 for health reasons. The drug was placed on the World Anti-Doping Agency and International Tennis Federation’s list of banned substances this year. Sharapova said she failed to open an email with the updated list of banned drugs.
Sharapova could lose millions if her endorsers ultimately decide to distance themselves from the scandal by dropping her. That puts Williams, the No. 2 highest-paid female athlete, in position to claim the No. 1 spot. Depending on the extent of the damage, it could also bump up Caroline Wozniacki, currently the third biggest endorsement earner.
"We are saddened and surprised by the news about Maria Sharapova,” Nike said in a statement. "We have decided to suspend our relationship with Maria while the investigation continues. We will continue to monitor the situation." That deal was reportedly valued at $70 million when she extended the eight-year contract in 2010.
"We regret the current news about Maria Sharapova. Until further details emerge and we are able to analyze the situation, we have decided to suspend planned activities," Porsche said in a statement.
Sharapova enjoyed the top spot among female athletes for pay for over a decade. In 2015, Forbes estimated Sharapova's total compensation at $29.7 million, including $23 million from endorsements. Williams, meanwhile, had a total compensation of $24.6 million, including an estimated $13 million from endorsements. The American holds deals with Nike and Gatorade, among others.
"I have let my fans down, and let the sport down that I have been playing since age of four that I love so deeply," Sharapova said. "I know that with this I face consequences and I don’t want to end my career this way. I really hope to be given another chance to play this game."
In their last meeting, Williams defeated Sharapova in the Australian Open quarterfinals.
For Fortune's annual crystal ball of predictions, we said that Williams could likely cash in on endorsement deals in 2016 after a successful 2015 that saw her claim the title of Sports Illustrated's Sportsperson of the Year. With Sharapova potentially sidelined, that could well prove true.
Fortune has reached out to Sharapova's and Williams' teams for comment.