Megan Rapinoe has called on Lionel Messi, Cristiano Ronaldo and Zlatan Ibrahimovic to break their silence over issues in football. 

The outspoken United States Women's National Team star is one of the leading voices in tackling discrimination within the sport but believes the top male footballers aren't doing enough. 

"I want to shout: 'Cristiano [Ronaldo], Leo [Messi], Zlatan [Ibrahimovic] - help me!'," Rapinoe said, per The Sun.

"These big stars don't engage in anything when there are so many problems in football! Are they afraid of losing everything? They might believe that but it's not true...

"Who would banish Messi or Ronaldo from the football world for speaking out against racism or sexism?"

Although the Argentine has stayed quiet on issues throughout his career, Ronaldo and Ibrahimovic have spoken out about racial abuse in the past. 

But the latter has previously caused controversy with his comments about the women's game, saying that they should just 'give up' back in 2013.

"With all respect for what the ladies have done, and they've done it fantastically well, you can't compare men's and women's football. Give it up, it's not even funny," he said, per ESPN.

Rapinoe is more than justified in calling top male stars to help her fight for equality. 

The 34-year-old won the Women's Ballon d'Or on Monday and is now officially recognised as the best female footballer in the world. 

She believes that speaking out on issues actually helped - rather than hindered - her win this week. 

"This Ballon d'Or rewards both. On the one hand, I am a very good footballer," she said when receiving the prize.

"On the other hand, my action off the field attracts support because people understand that I'm trying to find solutions to the problems of society.

"I'm lucky to have some talent to lead. I don't fear the consequences, so I say what to say.

"I'm exhausted from travelling for conferences and meetings but, if things need to improve in our world, so be it on the front line." 

Rapinoe's stance on fighting for what is right should be respected and if big names like Messi, Ronaldo and Ibrahimovic do start speaking out too, then it would only be a good thing.