[2] In August 2023, Jäger competed at the 2023 UCI Para-cycling Road World Championships and won a gold medal in the time trial T2 event, and a bronze medal in the road race T2 event.

He was subsequently named the Junior Para Athlete of the Year by Sporthilfe.

[3] In September 2024, Jäger represented Germany at the 2024 Summer Paralympics and finished in fourth place in the road race T1–2, and eighth place in the time trial T1–2.

[1][4] Weeks later, he then competed at the 2024 UCI Para-cycling Road World Championships and won a silver medal in the road race T2 event, finishing two seconds behind gold medalist Dennis Connors.

[5][6] Jäger suffered a parental stroke and has been paralyzed on the left side of his body since birth.