[3] On 24 June 2022, after one season with the youth team and two appearances for the senior side in the Danish Superliga, his contract was terminated after he expressed a desire to leave the club.
[4] Less than a month after leaving Randers, on 16 July 2022, Simmelhack joined fellow Danish Superliga club Copenhagen on a contract until 2025.
[6] On 30 August 2023, he was loaned out to AC Milan's youth team for the duration of the 2023–24 season, with an option for the deal to be made permanent.
[7] While at AC Milan, he reached the final of the UEFA Youth League, where his team lost 3–0 to Olympiacos.
[8][9] On 21 August 2024, Danish Superliga club Silkeborg announced the signing of Simmelhack on a contract until the end of 2027.