Last summer, Aaronson activated a clause in his contract to avoid playing in the Championship and secured a loan move to Union Berlin.
The American consistently featured for the Bundesliga team, making 38 appearances and netting two goals.

Yet, his time in Berlin is coming to an end.
Union Berlin has announced that Aaronson will return to Leeds after his loan period.
Whether Leeds intends to retain the winger or opt to transfer him again is currently uncertain.
Some criticized Aaronson for lacking the physicality needed for Premier League play, which affected his performance at Leeds.

Should Leeds secure a return to the Premier League, Daniel Farke will need to evaluate Aaronson’s role. Conversely, if Leeds does not achieve promotion, Aaronson may have the option to activate another loan clause.