We know so much about the players on the U.S. men’s soccer team these days, or at least we think we do.

We watch them every week on our TVs, computers, phones, and every other device imaginable. We see their exploits for some of the biggest clubs in the world, in the biggest leagues in the world: England’s Chelsea, Spain’s Barcelona, Italy’s Juventus, Germany’s Borussia Dortmund, and more.

We follow their interactions with each other on Twitter and Instagram, full of jokes and emojis and videos. We presume from this that they have chemistry that will show itself on the field when they play together.

And when they have played together, they’ve shown that to be true. Less often than anyone would like, thanks to the pandemic, but this summer’s Concacaf Nations League title win showed signs of what could be.

» READ MORE: Christian Pulisic helps make USMNT’s Concacaf Nations League win an epic chapter in U.S.-Mexico rivalry

There’s one big thing we don’t know yet. What will they do when they take the show on the road in World Cup qualifying? Will all the hype from the best collection of individual talent in U.S. men’s team history translate into results? And will those results avenge the still-haunting failure to qualify for the 2018 World Cup, and send the Americans to Qatar next year?

We can’t know until it happens. So we won’t know until the final whistle of Thursday’s 14-game qualifying tournament opener in El Salvador (10 p.m., CBS Sports Network and Universo).

The U.S. program has changed immensely since that infamous October night in Couva, Trinidad when it hit rock bottom — almost four full years ago.

More elite Americans than ever now thrive in Europe, with a record 12 U.S. players in this season’s Champions League group stage. Many, like former Union players Brenden Aaronson and Mark McKenzie, grew up with MLS teams and were sold abroad for big sums. They earned the right to displace the last generation of players, many of whom never made it to bigger stages than MLS.

Of the 25 U.S. players who will be at San Salvador’s Estadio Cuscatlán (which will be half-filled due to pandemic restrictions), just four were on hand in Couva: Christian Pulisic, Tim Ream, DeAndre Yedlin, and Kellyn Acosta. Only Ream is older than 30, and only Acosta — whose skill set fits a specific midfield role in the U.S. system — remains in the domestic league.

We know Pulisic is ready for what’s to come, and raring to go after a positive COVID-19 test sidelined him. Thankfully, he was fully vaccinated, so he wasn’t affected beyond having to sit for 10 days. The resulting lack of match fitness will keep him out of Thursday’s game. Goalkeeper Zack Steffen, from Downingtown, is also out due to back spasms. Matt Turner will start in his place.

» READ MORE: Christian Pulisic and Zack Steffen won’t play in the USMNT’s World Cup qualifying opener

So are the other big-name youngsters really ready? Will Weston McKennie, Sergiño Dest, Josh Sargent, Tyler Adams and Gio Reyna answer the bell? Will Aaronson, on a rocket-ship ascent with Red Bull Salzburg in Austria, step up with Pulisic out?

Adams and McKennie, who by their demeanors and central midfield roles are natural leaders, say their team is ready.

“There’s no Plan B for us — there’s only been a Plan A, and that’s obviously to qualify for the World Cup,” Adams said. “When I think about the experiences that we’ve had in the past two years, I would say as a group, how much we’ve developed, it’s ultimately for this moment right here. We’ve waited a long time for this.”

McKennie emphasized that he doesn’t feel burdened by the 2017 failure, though he knows many fans do.

“Obviously, it’s going to be in the back of our heads somewhere, but that’s not our main fuel,” he said. “Right now, we’re just trying to create a legacy of our own … We’re just looking forward to this new journey, a new cycle, and not trying to dwell on the past.”

U.S. manager Gregg Berhalter knows what’s coming especially well. Fourteen of his 44 U.S. national team appearances came in World Cup qualifiers, including a 2-0 win at El Salvador in 2004. These days, he has some of the first words in practice sessions, and will have some of the last words in the locker room before kickoff.

“One thing that gives me confidence is you have guys on the team that are playing for really high-level clubs, and their expectation is to win every single game they’re in,” Berhalter said. “There’s a different sense of urgency in these games, and a lot of times, we have a target on our backs as the United States ... I think we have the quality, and now it’s about, do we have the right mentality.”

After four hard years of waiting, it’s time to find out.

» READ MORE: How to watch all of this week's Concacaf World Cup qualifiers