United States women's national team star Megan Rapinoe has asked Cristiano Ronaldo, Lionel Messi and Zlatan Ibrahimovic to help join in the fight for equality in football.

The 34-year-old told France Football (h/t Jonathan Johnson at ESPN FC) that the game's biggest male superstars need to be more involved in football's big issues.

"I want to shout: 'Cristiano, Lionel, Zlatan, help me! These big stars do not engage in anything when there are so many problems in men's football.

"Do they fear losing everything? They believe that, but it is not true. Who will erase Messi or Ronaldo from world football history for a statement against racism or sexism?"

Rapinoe won the Ballon d'Or, given to the year's best female footballer, on Monday to cap a stellar 2019:

She was one of multiple captains on the United States team that won the FIFA World Cup in France in July and also won FIFA's The Best women's player prize in September.

Rapinoe is a powerful voice within the game and has said she feels like a "walking protest," per Henry Bushnell for Yahoo Sports.

She also chose to kneel during the United States national anthem in support of former San Francisco 49ers quarterback Colin Kaepernick's protest against racial and social injustice in 2016:

Rapinoe acknowledged that her Ballon d'Or win recognised her achievements both on and off the pitch, per Johnson.

"This Ballon d'Or rewards both," she said. "On the one hand, I am a good player. On the other, my activity away from the pitch brings me support as people understand I am acting to find solutions to our society's problems. The idea is to empower others to speak louder."

Ronaldo offered support to Napoli's Kalidou Koulibaly in December 2018 after the defender suffered racial abuse against Inter Milan.

Per Football Italia, the Juventus star posted a message on Instagram that read: "I always want education and respect in life and football. No to racism any other type of offence and discrimination!!!"

Messi, Ronaldo, Ibrahimovic and many other top stars have all featured in a UEFA video aimed at combating racism, but none has been willing to speak out against such modern issues in the same way as Rapinoe.