RB Salzburg batted away two bids for their midfielder in January as the Austrian side wanted to see the season out with Aaronson in their ranks. The clubs agreed on a £25m deal that would come into play at the conclusion of the 2021/2022 season provided United were still a Premier League side.
Aged just 21 years old, the American arrives at Elland Road with significant international and Champions League experience and will strengthen United's midfield options ahead of the 2022/2023 Premier League campaign.
Here, we take a look at Aaronson's impressive career so far:
Here, we take a look at Aaronson's impressive career so far: