As Morgan Brian ran onto the soccer field ahead of her first World Cup game Monday, U.S. teammate Kelley O'Hara sidled over with a suggestion.
"Enjoy the experience," O'Hara said.
Too late. Even before Brian got to Canada, she told herself to appreciate every moment of this tournament. Because there's no guarantee she'll play in another one.
"You never know," she said.
"This is something that is so cool to be at. You have to remember that it is a World Cup. It's something that we trained for our entire lives."
Brian, 22, is the youngest player on the team and the age gap with some of her teammates is considerable. For instance, defender Christie Rampone, 39, entered college the year Brian was born.
Yet, lost in the talk about the U.S. having the oldest and most experienced team in this tournament is the fact that eight players are making their World Cup debuts in Canada, among them Christen Press, 26, whose second-half goal put the U.S. ahead to stay in its 3-1 victory over Australia on Monday.
Newcomers Press, Sydney Leroux, Meghan Klingenberg and Julie Johnston started in Monday's game. Brian went into the game in the 86th minute, joining a lineup that included five players 30 or older.
And while there were a lot of opening-night nerves to settle — "There's some new players on the field in a big, big moment," U.S. Coach Jill Ellis said — with this World Cup being the longest and most physically challenging in history, the U.S. will need strong performances from the rookies and the veterans if the team is to make a long run.
"I love the fact that it's experience with youth," said midfielder Shannon Boxx, at 37 the second-oldest player on the team. "Jill did a great job with that. Because the World Cup is a different level. … The atmosphere is very different than anything you've ever seen before."
The tournament is also being played on artificial turf for the first time. That will punish old legs faster than young ones, further raising the importance of the World Cup rookies.
"We all know it's going to be a grind," said midfielder Carli Lloyd, 32, who is playing in her third World Cup. "We're going to need all 23 players to contribute to win this thing."
Brian is just trying to drink it all in.
"This is a once-in-a-lifetime opportunity," she said. "Obviously, I want to enjoy it. You don't want to take anything for granted."
That's the voice of experience speaking. Not Brian's, of course. Her experience is just beginning.
"They're veterans and they've been so many World Cups," Brian said. "And they still don't take it for granted.
"It's my first one. It's something you've just got to enjoy."
Midfielder Tobin Heath nodded in agreement. Her first World Cup was four years ago, when she played in four games as a substitute, including a final the U.S. lost to Japan on penalty kicks. And although she's only 27, she has 93 international appearances.
Players such as Brian can't match that experience. But Heath smiles when asked whether the rookies make up for it with the kind of youthful enthusiasm that reminds the older players that soccer is just a game.
"It's just so cool to see these young players evolve," Heath said. "I love our young talent. They deserve to be here. They're going to help this team go far."
Follow Kevin Baxter on Twitter @kbaxter11