Asger started his football career at Virklund Boldklub, he moved to Midtjylland's youth academy, where he met coach Brian Prisk, who was assistant coach at the time. In 2014 he transferred to Red Bull Salzburg. The almost two-metre tall centre-back subsequently played in Germany. He first moved to Regensburg in 2017, his next steps then led to Nuremberg. In the second highest German competition, he played 140 league games in five years. He transferred from Nuremberg to Sparta in the summer of 2022.