“I just try not to drop it,” Dahlkemper said.

The top players on the American team are acknowledged, even among their teammates, to be among its finest front-facing camera operators.

After a World Cup warm-up game this year in Alicante, Spain, an enormous crowd of fans congregated in the front rows of the elevated stands. What followed was a master class in stadium selfie line management.

Alex Morgan went left, Carli Lloyd went right, and the two proceeded to shuffle down the line with their backs to the railing. The fans, meanwhile, stretched their phones out toward the field, waiting for them to be grabbed by one of the players.

The dexterity on display was world class. The task demanded as much composure and coordination as any soccer drill: smile-click-pass, smile-click-pass, swiftly, again and again and again, until every fan had a picture.

“You should hear them screaming when they get to meet someone like Alex or Carli,” Mewis said. “It absolutely makes their day.”

The players go through this, in part, because many of them were once on the other side of the railing. Mewis in her youth cherished an autographed picture of the former striker Cindy Parlow. (“I kept it framed for, like, way too long into my 20s,” she said.) Sonnett still owns a Frisbee that bears the signatures of Hope Solo, Marta, Lloyd and many other star players.

Whether at United States matches or anywhere else top women’s players take the field, the players realize they are spiritual ambassadors for women’s soccer.