Yahoo Finance

On Monday afternoon, Maria Sharapova held a press conference to announce that after this year's Australian Open in January, she failed a drug test. By Monday night, the governing body of tennis had provisionally suspended her—and so had Nike (NKE).

Sharapova tested positive for a medication called Meldonium, which WADA, the World Anti-Doping Agency, added to its banned substance list in January. Sharapova said she has been taking the drug for 10 years to help with her blood flow and did not know that it had been banned. At her press conference, Sharapova said she was not leaving the sport and hoped she would get a second chance to play it.

Nonetheless, she has been temporarily suspended by tennis, effective March 12, and Nike said it was suspending its endorsement deal with her late on Monday evening. Porsche and Tag Heuer followed suit. In a statement, Nike said, "We are saddened and surprised by the news... We have decided to suspend our relationship with Maria while the investigation continues. We will continue to monitor the situation."

Sharapova has earned $36.76 million in prize money in her career, but more than three times that amount off the court in endorsements. She has active deals with Avon (AVP) beauty products and Head rackets. As of Tuesday afternoon, those sponsors hadn't issued statements. Danone, which owns another one of her sponsors, Evian water, did release a statement on Tuesday, saying that it was "surprised" by the news. Evian "has been a partner of Maria Sharapova for many years, and until now, we have maintained a trustworthy professional relationship... We will follow closely the development of the investigation," Danone said.

What is perhaps most interesting here isn't that Nike suspended Sharapova, but how swiftly it did so. In other cases where Nike dropped an athlete over performance-enhancing drugs, it took days to make the decision, and sometimes weeks. It's curious that with Sharapova, the brand dropped the hammer in a matter of hours—especially considering the complexity of the situation.

Here are 5 other pro athletes who lost their Nike endoresements, plus one who, surprisingly, did not:

Adrian Peterson

Minnesota Vikings running back Adrian Peterson was indicted for child abuse charges on Sept. 12, 2014. Radisson Hotels ended its team sponsorship of the Vikings the next day. Five days later, Nike ended its personal endorsement deal with Peterson, saying in a statement that the company "in no way condones child abuse or domestic violence of any kind."

Ray Rice

After video footage leaked in February 2014 of Baltimore Ravens running back Ray Rice dragging his fiancé out of a casino elevator, sports equipment company Vertimax issued a wait-and-see statement, then dropped him in June. But it took all the way until September—when new video came out, nearly seven months after the scandal started, that showed Rice striking his fiancé—for Nike to end its endorsement. Dick's Sporting Goods (DKS) also pulled the player's jersey from stores, and EA Sports scrubbed him from its Madden NFL '15 game.