Savannah DeMelo said the reality that she was playing for the United States in the Women’s World Cup finally hit her as the fans in the stadium counted down the final 10 seconds before her first match. She only started to get truly comfortable, though, once people starting kicking her.

The hair pulls and the shoves and the elbows? Those were just a bit of welcome familiarity for DeMelo, one of the most fouled players in the National Women’s Soccer League. “I’m used to getting kicked,” DeMelo said.

It is all the rest that is still new: the global stage; the sky-high expectations inside and outside the U.S. team; the constant pressure to not let down a squad that has won the last two World Cups. DeMelo, after all, had never played a game for the United States before she was named to the World Cup roster last month.

Her inclusion, as the least experienced of the 14 World Cup rookies on the U.S. roster, was one of the biggest surprises of the Americans’ run-up to the tournament. But it has been her presence in Coach Vlatko Andonovski’s starting lineup, and the role she has been asked to play as a midfield orchestrator and instigator, that could prove pivotal as the United States tries to navigate its way through the knockout rounds of the tournament.

Named as a starter in the United States’ first two World Cup games, DeMelo, 25, has been a reliable fit for the position normally filled by Rose Lavelle, who arrived at the World Cup still working her way back to full fitness after an injury-marred spring.

While Andonovski manages Lavelle’s minutes — he has said he prefers to have her finish games than start them, for now — DeMelo took her place in the U.S. games against Vietnam and the Netherlands.

“Rose brings a creativity to the team, a fluidity,” said Andi Sullivan, who has started alongside both Lavelle and DeMelo for the national team. “And for me, having played with her for a long time, I know where she’s gonna be.”

But Sullivan added that DeMelo has been a seamless replacement, “and I think it’s been awesome have both Rose and Savannah play in that position, because they both bring such awesome qualities on the ball, on the dribble, interchanging positions.”

Andonovski saw a place for DeMelo in his team months ago.

He first called her into camp last year, both to reward DeMelo’s performances for Racing Louisville, where she had been one of the league’s top players as a rookie, but also, perhaps, to see how she fit within the group of World Cup winners and eager rookies he was assembling to take to New Zealand and Australia.

Coach and player kept up a regular exchange of text messages and critiques through the winter, the first sign for DeMelo that she might have a shot to win a place on the World Cup team despite her relative inexperience. The problem, she knew, was that she might not have a lot of chances to show the national team coaching staff what she could do.

In January, she said last week, she realized there would only be one camp before the World Cup, and she remembered that Andonovski had told the team he would be closely watching their performances in club games. So she resolved to follow some advice her father, a soccer coach, had always repeated about “controlling the controllables.” She vowed to focus on her play for Louisville, and “make it almost like they couldn’t not take me.”

The goals followed, five in 12 games this season. But when DeMelo and the rest of the team got an email setting the day when Andonovski would call them individually to tell them if they had made the World Cup team, all her stresses came back. The news, though, was exactly what she wanted to hear.

Keeping her place in the lineup, though, is not a given. The U.S. has struggled to finish its chances in its first two games, and Andonovski spoke last week about “how can we help the players that are in a position to finish, giving them a little bit of service, whether it’s finding them on the right step or the proper foot, the final touch — the service before the finish.”

That creativity is what Lavelle has offered in her two relief appearances. She brought an urgency to the Americans’ attack in the opener against Vietnam, when she entered after the first hour. She did the same against the Netherlands, when she replaced DeMelo at halftime, restored some bite to a midfield that was being bullied and outplayed, and delivered the assist on Lindsey Horan’s tying goal.

Andonovski has been purposely vague about when Lavelle might be fit enough to go 90 minutes. Instead, he has preached the value of getting game-time minutes for his inexperienced starting lineup, a preference so strong that he only made one of his five available substitutions as his team pressed for a winning goal in its draw against the Netherlands on Saturday.

Lavelle had replaced DeMelo by then, and she may offer do the same on Tuesday against Portugal, perhaps even earlier. The team will find out the lineup on Monday night. But DeMelo said she won’t be looking over her shoulder.

“The reason I’m here is just to be myself,” DeMelo said, “so that’s what I kind of want to bring to the team.”