REIMS, France — The U.S. women’s soccer team has waited four years to begin defending its World Cup trophy, a period that included a humbling fall at the Olympics, the departure of some and the infusion of others, tactical experiments, a strategic re-set and a promising buildup.

So what’s a few extra days longer?

When the 24-team tournament began across France late last week, with the reigning champions as slight favorites and the hosts mounting a grave threat, the Americans were forced to wait and watch a little longer.

The last teams to play their first group match, the U.S. will take on Thailand on Tuesday night.

“We’re feeling left out,” forward Alex Morgan joked Monday.

Judging from comments in recent days and the general good vibes emanating from U.S. training camps — in multiple U.S. venues, then London and now this lovely city 90 miles northeast of Paris — the Americans are aching to get started.

“When the tournament kicks off and you watch the games, the anticipation for your first match grows,” said Jill Ellis, who will attempt to coach the U.S. team to consecutive Cup titles for the first time in its illustrious history. “The players are ready, excited, hungry. We feel prepared. The process has been a long one, but the preparation has been excellent.”

The U.S. is expected to easily clear the first two hurdles — Thailand is ranked No. 34, Chile No. 39 — before encountering stouter resistance in the Group F finale against Sweden.

From there, in a women’s environment that has grown more competitive, the real tests will begin. If the U.S. and third-ranked France don’t stumble along the way, they will collide in the quarterfinals.

For now, the focus is on the group.

“You can’t get beyond the first game because there are so many twists and turns in this plot, you just have to be ready to tack in terms of absorb or examine what is in front of you,” Ellis said. “To get too forward ahead could be problematic. There are so many unknowns out there. I feel very confident in our preparation for the unknowns.”

What is known is that this U.S. team retained 12 of 23 players from the 2015 squad that routed Japan 5-2 in the Cup final. It’s the oldest team in the tourney, with an average age of 28.5, and the most experienced (five players have appeared in 10 or more World Cup matches).

It features a lethal frontline (Morgan, Megan Rapinoe and Tobin Heath) and enough depth to field two squads. Carli Lloyd, hat-trick hero of the 2015 final, and rising star Mallory Pugh are bench options.

“It’s been unique and exciting to watch this team grow over the last three years,” retired forward Abby Wambach said. “They are just kind of getting started.”

Morgan alluded to this group seeking to forge its own identity, saying, “Many of the players were not a part of (2015). There is just a different feel and it feels great. This team is ready to go. I feel like we are in peak form and ready to find success for the first time in this tournament as ’19ers.”

The reference to ’19ers comes 20 years after the famed “?’99ers,” led by Mia Hamm, Michelle Akers and Julie Foudy, won the program’s second world title.

This team will have to navigate a diversifying field of true contenders (France, No. 2 Germany), an emerging European class (Netherlands, Spain, Italy) and perennial threats (Canada, Australia, Japan, Sweden, England).

“The gap from top to bottom has continued to close over the years,” defender Kelley O’Hara said, “and this is the tightest it’s ever been.”