Over the next eight days, we are going to learn a lot about the U.S. men's national team.
We are going to learn about how they fare against their top rivals once again. We are going to learn about which young players can step up, which players are important and which are irreplacable.
But, most importantly, we are going to learn exactly where they stand as we reach the midway point of World Cup qualifiers.
Through the first six games of CONCACAF qualifying, the U.S. is sitting relatively pretty. They are second in the table, behind only Mexico, ahead of their clash with El Tri on Friday and a visit to Jamaica next week.
If the USMNT wins those two games, they can begin to truly dream of Qatar next winter. But should they lose or even drop points, and the path towards the World Cup will only get trickier.
So which players will make the difference? Which absences will be noticeable? What will be the positions that determine success or failure for this team?
Here's a look at five things to watch for in the November qualifiers:
Pulisic's return
Christian Pulisic is back with the national team for the first time September, but naturally his return comes with a few question marks surrounding it.
The first, and most important, comes regarding his fitness. Pulisic has yet to play a full 90 minutes since returning for Chelsea, making two cameo appearances in the last week to mark his recovery from injury.
After opting to bring Pulisic in, USMNT boss Gregg Berhalter said last week that the Chelsea star's minutes will depend on how well he trains this week. And, after giving Pulisic a few minutes off the bench, Thomas Tuchel all but pleaded with the USMNT to be careful with their star winger.
"Hopefully everybody, including himself, is responsible and doesn’t get carried away by emotions and by helping his country to win a super important match," Tuchel said this weekend . "Hopefully it all goes well and the minutes will elevate him and he will come back stronger.”
So that leads to the second question: is the USMNT better with a less-than-fit Pulisic on the field? Given Brenden Aaronson's form with the USMNT, the answer may actually be no.
Aaronson has been the USMNT's most consistent performer over the last few months, and has more than earned his place as a starting winger on this team.
And, if not for the absence of Gio Reyna, it would make plenty of sense to use Pulisic as a supersub. Berhalter could easily turn to veteran Paul Arriola or the dynamic Tim Weah against Mexico, with Jesus Ferreira less likely to play due to his inexperience.
But, as Berhalter said, that will all depend on how Pulisic looks in the days to come, and how the USMNT will look to balance his minutes over the next few days.
A leap of faith with Pepi
If you were not sure if Ricardo Pepi was the USMNT's go-to striker before, then this roster certainly removed all doubt.
Pepi is the only true No.9 in the USMNT squad, as Berhalter has all but declared the FC Dallas teenager the USMNT's first-choice centre forward.
Berhalter said that Weah could start up top while Ferreira or even Pulisic could also feature as a No.9 in his system, but make no mistake: this is Pepi's time.
With Pepi as the lone No.9, Berhalter opted not to select the likes of Josh Sargent, Daryl Dike and Jordan Pefok, with Dike, in particular, in spectatcular form for Orlando City.
As things stand, Pepi is the perfect blend of everything Berhalter is looking for and, despite the fact that he is just a few months into his USMNT career, the coach says he's fully comfortable with the 18-year-old being his guy.
“We want dynamic movement in the penalty box," Berhalter said of the decision. "These type of things are important. Daryl, I think is getting back to his form. I think he will have a role to play with the national team in the future, I think it's just not exactly where we need it to be right now.
"Jordan, similar, he's a strong, physical forward, more of a stationary type of forward, a hold-up player. And we're looking for guys that are running a little bit more.”
Pepi, so far, has been that player. But, as he prepares to face Mexico, he is now staring down his biggest test yet.
Brooks' exclusion
For years, John Brooks is a player that would be one of the first names on the USMNT teamsheet in a must-win game. It appears, though, that that is no longer the case.
Brooks was left out of this squad in one of the more glaring omissions, with his form in recent USMNT games the deciding factor.
A towering, game-changing central defender in the Bundesliga, Brooks has struggled to replicate those performances in a USMNT shirt, especially in the trenches of CONCACAF.
Brooks, to his credit, took it in stride, admitted his faults and promised to come back stronger. Berhalter, in response, was full of praise for the Wolfsburg star's ability and mentality.
This is not the last we have seen of Brooks and if the U.S. started the World Cup tomorrow, there is no doubt that he would be in the squad. But heading into this break, the U.S. will get a chance to look at several different options.
Miles Robinson has usurped Brook as the USMNT's undroppable centerback, and is basically a lock to start whenever fit.
Next to him, Berhalter could turn to the youthful talent of Chris Richards, who is growing up in a big way in the Bundesliga himself, or Mark McKenzie, who has made the leap to Europe successfully with Genk.
He could also look to a veteran in Walker Zimmerman, especially in what should be a battle against Mexico.
One of those guys may seize the opportunity, much like Robinson has. Or the job may still be Brooks' to lose going forward. But there are certainly some question marks in defence these days.
Busio's breakout?
If you wanted a pick for a player that could be this window's breakout star, the answer is Gianluca Busio.
Busio has wasted no time in adjusting to life in Serie A, immediately become a key player for Venezia. Just this weekend, Busio had two key passes, three tackles and completed nearly 90 per cent of his passes in the newly-promoted side's shock win over Roma.
Not bad for a 19-year-old midfielder.
When asked about Busio, Berhalter said that he fully expects the former Sporting KC midfielder to be a key player this window after bringing him along relatively slowly so far.
"Gianluca will definitely be pushing for a starting position," Berhalter said. "He's been in great form with Venezia. He's ended up being a key player.
"When you talk about a young player's transition to Europe, especially the level he went to, he's handled this better than just about about anyone I've seen.
"It's been absolutely amazing to see his transition into Serie A. He's done a great job and he's in good form right now."
Busio's surge could be bad news for Yunus Musah, a player that has not locked down a starting spot at Valencia and does not quite offer as much in defense as Busio does.
With Tyler Adams and Weston McKennie's names written on the team sheet in Sharpie, this is Busio's chance to put his name into the mix as that ball-carrying, creative midfielder alongside them.
Sergino out, Scally in
Especially given his efforts last camp, the lost of Sergino Dest is a tough one for the USMNT. When he is on his game, the Barcelona defender really can be unplayable at CONCACAF level, with his ability to create ridiculous amounts of mismatches and, ultimately, goals.
But Dest is not here having suffered an injury with Barcelona. And so the door opens for a different type of fullback: Joe Scally.
Scally is not as dynamic as Dest is on the attacking end. Few are, to be fair. But, defensively, the teenage defender is already asserting himself as a legitimate monster just a few months into his Bundesliga career.
The former NYCFC defender has quickly proven himself a key member of the Borussia Monchengladbach squad, playing on both the left and the right side of the defence.
He has shined in two wins over Bayern Munich, staring down some of the best wide players in the world without blinking.
Berhalter admitted last month that Scally was nearing his USMNT call-up, and this is his first chance to show his game on the international level.
It remains to be seen if the 18-year-old will get the nod against Mexico, especially with veterans DeAndre Yedlin and Reggie Cannon on the right and first-choice left-back Antonee Robinson on the other side.
But Scally is certainly one for the future and, given how he can impact a game defensively, there is a chance he can be one for the present too.