The Union are in talks to sell midfielder Brenden Aaronson to Austrian club Red Bull Salzburg, multiple sources told The Inquirer on Wednesday after Major League Soccer’s website reported that a verbal agreement was in place.

All of the sources cautioned that the deal — which would see Aaronson leave Philadelphia at the end of the Union’s season — is not done yet. Among many remaining factors, Aaronson needs to pass medical exams with Salzburg, and those exams will have to be done in the U.S. because of coronavirus-enforced travel restrictions.

But it seems increasingly clear that Aaronson, a 19-year-old Medford native, is on the way to becoming the first product of the Union’s youth academy to be sold abroad. It’s a benchmark the team has long awaited, and has invested millions of dollars over the years to achieve.

It’s no fluke that Salzburg is the expected destination. The club is the former home of Union sporting director Ernst Tanner, and the current home of American manager Jesse Marsch, a close friend of Union manager Jim Curtin from their playing days together in the 2000s.

Nor is it a fluke that Aaronson has reached this point. His passing, dribbling, and high-pressing skills as an attacking midfielder — plus a rapidly developing shooting touch — make him an ideal attraction for European teams.

Salzburg has been the leading candidate to acquire Aaronson for some time. At various points, the race also included Scotland’s Celtic and multiple German clubs, most notably Hoffenheim — another of Tanner’s past stops — and Eintracht Frankfurt. But when Salzburg showed serious interest, it moved to the front of the pack.

The Austrian club has become one of Europe’s hottest launchpads for young prospects in the last few years. Famous alumni include Liverpool’s Sadio Mané, Naby Keïta, and Takumi Minamino; RB Leipzig’s Dayot Upamecano, arguably the world’s top centerback prospect; and Borussia Dortmund’s Erling Haaland, a global sensation for his piles of goals.

Tanner was personally involved in the development of Mané and Keïta. Marsch helped launch Haaland and Minamino to stardom in last season’s Champions League.

» READ MORE: Ernst Tanner has a history of developing top soccer prospects

Salzburg, Leipzig, and MLS’s New York Red Bulls are part of the same global conglomerate run by the Red Bull energy drinks brand. It certainly won’t be lost on Union fans that their team just sold its brightest prospect to a team affiliated with its biggest rival.

But Salzburg is really an ideal destination for Aaronson. The team is a tie away from playing in the Champions League group stage for the second straight year, and he’d be eligible to take part when he arrives.

Marsch is a terrific manager with a track record that includes the 2015 MLS Supporters’ Shield and coach of the year award. The Princeton alum had a major hand in developing current U.S. national team star Tyler Adams, then moved to Leipzig in July 2018 to become an assistant coach. Five months after that, Leipzig bought Adams from New York for a reported $3 million and a 33% sell-on fee.

In June 2019, Marsch got the top job at Salzburg. And in August of this year, Adams scored the goal that sent Leipzig to the Champions League semifinals, the biggest goal ever by an American player for a European club.