Ayuk, a 21-year-old Cameroon native, was an interesting prospect when he joined the team in 2015, playing 28 games that season. But he only made one appearance in 2016, and hasn't suited up for the team since then. He was loaned to Swedish club Jönköpings Södra last year, and has played four times for Bethlehem Steel this year.
Along the way, he played for Cameroon's national team at the 2017 under-20 Africa Cup of Nations.
Because Ernst Tanner still hasn't officially moved to Philadelphia yet due to visa paperwork delays, Union technical director Chris Albright handled the team's side of the negotiations.