More than 3.7 million people follow the Patriots’ Antonio Brown on Instagram, and a fair chunk of them do, presumably, not just because he is one of the best receivers playing the country’s most popular sport.

Brown, 31, is now ensnared in a maelstrom, with the attention that he draws as an athlete spotlighting a federal lawsuit that accuses him of sexual assault and rape, while also bringing more scrutiny to the N.F.L.’s handling of reports of violence against women.

A woman who had worked as Brown’s trainer is the plaintiff in the lawsuit, which was filed on Tuesday. The woman, a former gymnast named Britney Taylor who met Brown about 10 years ago when they were students at Central Michigan, described three assaults in the court filing, two in June 2017 and another in May 2018.

Profane messages from Brown to Taylor are presented as evidence in the lawsuit, which also says that when Taylor returned to Brown’s home in South Florida to retrieve some personal effects on the day after she claims he raped her, she wanted to discuss what had happened and Brown replied that she “made me feel like a real rapist.”