Asllani at the age of six began playing football with the academy of BFC Dynamo in 2008, where after eight years it was transferred to Union Berlin.

[3] On 15 December 2020, he made his debut with second team in a 2–0 home win against Eintracht Stadtallendorf after coming on as a substitute in the 59th minute in place of Maximilian Beier.

[4] His senior debut with 1899 Hoffenheim came on 20 November 2021, in a league match against RB Leipzig after coming on as a substitute in the 89th minute in place of Ihlas Bebou.

[7] On 7 October 2023, he scored his first goal for Austria Wien in his fifth appearance for the club in a 4–0 home win over Blau-Weiß Linz in Austrian Bundesliga.

[14] His debut with Germany U18 came three days later in the match against Serbia U18 after being named in the starting line-up and scored his side's only goal during a 1–2 away defeat.