Avdalas began his professional career in 2021, with the Greek powerhouse Panathinaikos, under coaches Dimitrios Priftis and Georgios Vovoras.
On September 20, 2023, Avdalas was loaned to the Greek Basket League team Karditsa for the 2023–2024 campaign.
On July 25, 2024, Avdalas was loaned once more to the Basketball Champions League semi-finalists Peristeri for the 2024–2025 campaign.
Participating teams at that tournament included Greece Under-16, Croatia Under-16, Poland Under-16 and North Macedonia Under-16.
[2] Avdalas was the leading scorer of Greece during the tournament, with 68 total points scored, in four games played.