Aspropotamitis signed his 1st professional senior contract with the Western Sydney Wanderers on 31 May 2015.
Early in the 2015–16 season Aspropotamitis got the opportunity to fill in for the experienced Alberto Aguilar who sustained an injury in the round 4 encounter v Perth Glory. An assured display from the young centre back, coupled with the Wanderers first win of the season, lead to his selection over the following weeks.
A string of solid performances lead the Wanderers to move quickly and extend the young centre backs contract for a further 2 seasons, Wanderers CEO said of the signing "We think he will continue to develop here and really go to the next level as a centre back. He has the maturity, the composure and the determination to become a very important player for this club and we are delighted to have him sign for an additional two years."[3]
In November 2020, Aspropotamitis was selected as part of the 2020 AFC Asian Champions League squad which played out the remaining games, which were originally postponed due the COVID-19 pandemic, in Qatar.[6] He scored Perth Glory's first ever goal in continental competition in a 1–2 loss against Shanghai Shenhua.[7]
On 28 December 2023, Macarthur announced that a transfer had been agreed with a club based in Asia, pending a medical evaluation from his future club.[9]
Pohang Steelers
Aspropotamitis joined Pohang Steelers ahead of the 2023 KLeague 1 season
He made his debut on February 14 in the Asian Champions League R16 clash v Jeonbuk Motors and his Leage debut in the season opener v Ulsan Hyundai.