WASHINGTON — U.S. soccer star Megan Rapinoe endorsed Sen. Elizabeth Warren, D-Mass., in the 2020 Democratic primary on Friday.

In a tweet, the women's national team co-captain said she was "proud" to back Warren "for being bold, for being real, for listening to ALL of us, and for being prepared to navigate the unique challenges we face today as a country."

"I just don’t think we can get to a better place by walking a moderate line so I appreciate you being out front and being big and bold with that," Rapinoe said in the video she shared on social media of her and Warren speaking on the phone.

I truly believe the best things in life are a result of being bold and being real. I’m proud to endorse Elizabeth Warren today, for being bold, for being real, for listening to ALL of us, and for being prepared to navigate the unique challenges we face today as a country @ewarren pic.twitter.com/9hX3gQYjvo — Megan Rapinoe (@mPinoe) December 13, 2019

Warren, in a statement, called Rapinoe "a champion of justice on and off the field and a role model for women and girls everywhere."

"I am honored to have her endorsement, and look forward to fighting alongside her for big, structural change," Warren said.

Rapinoe helped lead the team to its second World Cup title in a row earlier this year, and was named Sports Illustrated's "Sportsperson of the Year” earlier this week, one of only a few women to have received the title. The team as a whole was named Time Magazine's 2019 Athlete of the Year.

“I would love to endorse you and be on and your team and help in any way that I can. Consider me team Warren,” Rapinoe continued in the video posted Friday.

The 34-year-old soccer star has been vocal about her political beliefs, leading the team in a fight for equal pay and advocating for LGBTQ rights. Rapinoe has also been critical of President Donald Trump.

During the 2019 World Cup championship, Rapinoe said that even if the U.S. team won, she would not go “to the f---ing White House" for the celebratory visit with the president, as is tradition.

Trump shot back, tweeting that “Megan should never disrespect our Country, the White House, or our Flag, especially since so much has been done for her & the team.”

Rapinoe publicly backed Hillary Clinton in the 2016 general election and appeared at a campaign event with her to discuss equal pay.

Lauren Egan reported from Washington, Ali Vitali from Alexandria, Virginia, and Deepa Shivaram from Manchester, New Hampshire.