Brenden Aaronson and Mark McKenzie were named Monday to the U.S. men’s soccer team’s 22-player squad for a Dec. 9 friendly against El Salvador in Fort Lauderdale, Fla.

On paper, it was a small step for them. U.S. coach Gregg Berhalter picked an entirely MLS-based team, since most teams are done for the year, for a game that isn’t in a FIFA window. It’s a scouting exercise as much as anything.

But for Aaronson and McKenzie, it’s more than just a chance to play organized soccer for the first time since the Union’s season ended. This will likely be the last domestic camp they take part in for many years.

Aaronson will move to Austria in a few weeks, and become formally eligible to play for Red Bull Salzburg on Jan. 1. McKenzie is expected to also move to Europe this winter. Once they do, they will only join the national team for its big events, just like Christian Pulisic, Gio Reyna, and other stars.

» READ MORE: Union sell Brenden Aaronson to Red Bull Salzburg for $6 million, launching the Medford native to Europe’s soccer spotlight

The elevated stage on which they’ll be performing will bring them elevated statures, and an elevated path toward the highest levels of the sport. If Aaronson and McKenzie keep growing from the potential they showed with the Union, they’ll become prime candidates to make the 2022 World Cup team — the pinnacle of the sport.

If you’re a soccer fan, that makes total sense. If you’re new to the sport — if you’re the kind of person who watched the Union for the first time this year — let’s stop here, and answer a question that has come up repeatedly this fall: Why are the Union getting rid of some of their best players and harming their chances of winning a championship for Philadelphia, which is the pinnacle of sporting accomplishment here?

The answer, bluntly, is that the pinnacle of soccer is not winning a championship for Philadelphia. The pinnacle of soccer is winning a World Cup. Aaronson and McKenzie won’t do it playing for the Union, and the United States won’t do it keeping its best young players in MLS forever.

That isn’t how things traditionally work in a town where the only sports that matter are football, baseball, basketball, and hockey. But it’s how things work in the world’s game, and Philadelphia is a bigger part of it than ever before.

In fact, Aaronson and McKenzie have the potential to help Philadelphia achieve a soccer feat not seen since 1934. That was the last time a U.S. men’s World Cup team had at least four Philadelphia-area natives on it. The most famous was future Hall of Famer Francis “Hun” Ryan, whose family still has deep roots here today.

The 2022 team could have Aaronson (Medford), McKenzie (Bear, Del.), Pulisic (Hershey) and Zack Steffen (Downingtown) on the squad. There’s still much work to do before then, but the potential is real.

» READ MORE: Zack Steffen has it all at Manchester City, except the one thing he needs most

Understand this too, just as bluntly: The Union should actually get better from these moves. Add the cash they’ll bank from selling McKenzie and potentially Kai Wagner to the $6 million they’ve banked from selling Aaronson — plus up to $3 million more in performance incentives — and they’ll have an unprecedented war chest to use on buying top-level designated players.

All six teams left alive in the playoffs have the full quotient of three DPs: New England, Columbus, Kansas City, Seattle, Minnesota, and Dallas. The players aren’t all household names, but they have the talent and they’re showing up in the postseason. The Union, meanwhile, have only one designated player right now, Jamiro Monteiro.

This is how life is for every team in world soccer, except a few dozen in Europe’s upper crust that make billions in TV money. From Brazil to Mexico to France to Nigeria, the smartest teams in the sport develop players, sell them on, and use that money to buy and develop better players.

Now it’s the Union’s turn to go down that path. If they continue on it, they will become a far bigger deal than they’ve ever been, and fans likely won’t have to wait another decade for the next trophy.

» READ MORE: Brenden Aaronson’s emotional Union farewell will be remembered far longer than the playoff loss

U.S. roster

Goalkeepers (3): CJ Dos Santos (Benfica, Portugal; born in Philadelphia), Bill Hamid (D.C. United), David Ochoa (Real Salt Lake)

Defenders (8): Julian Araujo (Los Angeles Galaxy), Kyle Duncan (New York Red Bulls), Marco Farfan (Portland Timbers), Aaron Long (New York Red Bulls), Mark McKenzie (Union), Mauricio Pineda (Chicago Fire), Sam Vines (Colorado Rapids), Walker Zimmerman (Nashville SC)

Midfielders (5): Brenden Aaronson (Union), Kellyn Acosta (Colorado Rapids), Frankie Amaya (FC Cincinnati), Cole Bassett (Colorado Rapids), Sebastian Lletget (Los Angeles Galaxy)

Forwards (6): Ayo Akinola (Toronto FC), Efrain Alvarez (Los Angeles Galaxy), Paul Arriola (D.C. United), Daryl Dike (Orlando City), Djordje Mihailovic (Chicago Fire), Chris Mueller (Orlando City)

Notes

Dos Santos is a Philadelphia native who was in the Union’s youth academy for a time, then moved to Portugal as a 16-year-old in 2016 to join Benfica’s academy. He played for the U.S at the Under-17 World Cup in 2017 and the Under-20 World Cup last year. Now 20 years old, he’s on Benfica’s reserve team this season after graduating from the club’s under-23 squad.

Alvarez is a Mexican-American dual national who is being recruited by both countries. He played for Mexico at the Under-17 World Cup, which means he’s ineligible to play for the United States unless he choses to commit fully and files paperwork with FIFA.

More players might join the roster depending on how the rest of the MLS playoffs go. Columbus’ Gyasi Zardes, Seattle’s Jordan Morris and Cristian Roldan, Kansas City’s Gianluca Busio, and Dallas’ Bryan Reynolds, Jesus Ferreira, and Ricardo Pepi are candidates.