Want a sense of how much McCall Zerboni means to the North Carolina Courage? Check out the Twitter account of Paul Riley, her head coach. When Zerboni, the Courge’s fearless midfielder, was in the midst of a National Women’s Soccer League Best XI-caliber season in 2017, her coach took to Twitter to compare her ability to cover every inch of the field to that of a zamboni’s ability to cover every inch of a hockey rink. And this past April, Riley tweeted that Zerboni is a “warrior” just like U.S. soccer great Christie Rampone was. But when Zerboni made history in the Courage’s 4-1 win at Seattle Reign FC on June 23 by becoming the first player in NWSL history to play more than 10,000 regular-season minutes, Riley succinctly summarized the 31-year-old, box-to-box midfielder’s value. “All I can say is she is the heartbeat of the team: worker, thinker, talker, and a motivational machine,” Riley tweeted. “Privilege to coach her everyday. Getting better with every game. “10,000 minutes CONGRATS McCall. Exceptional talent and awesome woman. Cheers to 10,000 more. #nofinishlineever4u.” Riley’s message checked all the boxes regarding Zerboni’s importance to her teammates. On a star-filled team that scores at will, Zerboni plays just as an important role in the center of the park. A physical aggressor, she can shut down other teams’ attacks, get under the skin of opponents with her consistently high work rate, and this year, find the back of the net herself. (Through only 15 games, Zerboni has already scored three goals, matching her best single-season NWSL output).

More than anything, however, Zerboni has been all of the above on a consistent basis, a reality reflected in her becoming the first player in league history to cross the 10,000-minute mark. In the lead-up to reaching the milestone, Zerboni didn’t know she was close to making history, but once she found out after the fact, she said the achievement reminded her of all she’s come across throughout her career, one that continues to bring about new accomplishments.

“It’s definitely a milestone mark. It just reminds me of my journey and where I’ve been and who I’ve come in contact with along the way,” Zerboni, who recently made her second appearance for the U.S Women’s National Team in June, said, “and the joy and success I’ve had throughout it.”

Becoming the first in the league to reach 10,000 regular-season minutes doesn’t happen by mistake. In a sport where the delicacy of a player-coach relationship can jeopardize an individual’s spot in a team, Zerboni has had an incredible relationship with Riley, for whom she also played for with Portland Thorns FC and the Western New York Flash before the team relocated to Cary last season.

“He’s been the peak of my journey,” Zerboni said of Riley, adding that he’s “the perfect balance” in terms of pushing her but also giving her the freedom to do her own thing on the field.

Taking care of herself mentally and emotionally is what Zerboni attributes to her ability to remain fit physically and avoid injuries.

“When you’re enjoying what you do and you’re happy and healthy emotionally (on the inside), you’re willing to put the work in outside,” she said.

Last season, Zerboni played in and started all but one of the Courage’s 24 regular-season matches, and has gone the full 90 minutes in each of her 15 starts in 2018. (Like several of her Courage teammates, Zerboni missed the team’s June 3 match against the Houston Dash because of her call up to the USWNT.) But beyond staying healthy and being coachable, Zerboni has simply turned in the type of performances coaches desire from their players game after game, season after season. In each of her first five NWSL campaigns, Zerboni started at least 18 matches, and is on track to do so this season; of her 120 league appearances, 118 have been starts. “Any player can have a great game,” Zerboni said, “but it’s no good if you have a crap game the next day. Consistency is the best thing you can give to a team.” Continued improvement, with that consistency, is valuable to a team, too. Zerboni has brought just that to the Courage. While her ability to carve out a spot for herself in starting lineups throughout the NWSL has undoubtedly been impressive, Zerboni’s emergence as a national-team-caliber player eight-plus years into her professional career is just as – if not more – commendable.

Perhaps the leading example in U.S. women’s soccer of the idea that players can continue to improve on a year-by-year basis deep into their careers, Zerboni is proving that players don’t have to necessarily plateau once they become established mainstays in the women’s soccer landscape.

“McCall is definitely still improving. It’s so cool to be out on the field with her and see her game grow every day,” said Samantha Mewis, one of Zerboni’s partners in the midfield. “It’s what everybody’s goal really should be: to continue learning. I think it says a lot about the environment Paul (Riley) has created here, but it says a lot about McCall, too.

“She isn’t settled, she continues to push, continuing to want to get better and continuing to do all those things everyday to enable that to happen.”

The catalyst behind Zerboni’s growth seems to be an ever-present desire for new ways to get better, which remains even after all the minutes she’s played.

“I guess 10,000 is a marker, but for me it’s just a baseline to go further and push harder and improve from there,” she said. “Obviously I’m an experienced player, so I’ve got to gain more experience and add more calibers to my game, somehow, after 10,000 minutes.”

On Twitter, Riley said, “Cheers to 10,000 more” minutes for Zerboni. She might just get there with that attitude.