Avdija was born Jan. 3, 2001 in Beit Zera, Israel. His father, Zufer, was a professional basketball player. His mother, Sharon, was also a basketball player, plus a track and field athlete. Avdija holds dual citizenship between Israel and Sebia -- his father is a Serbian citizen. Avdija originally played soccer, but focused on basketball in the fourth grade. From 2017 to 2019, Avdija led the Maccabi Tel Aviv hoops squad to three consecutive Israeli youth state championships. In August 2018 in Belgrade, he participated in Basketball Without Borders Europe, where he earned camp MVP honors. After three seasons on Israel's junior national team, Avdija joined the senior team in February of 2019. When Avdija turned 18, he received a deferment from mandatory military service in Israel due to his basketball career. However, he was drafted into a short service program in April of 2020 due to the COVID-19 pandemic suspending basketball. Avdija began his professional career in Israel with Maccabi FOX Tel Aviv in 2017-18, though appeared in just three games that season. The following year, he fluctuated between the main club and the Junior Team, averaging 6.1 points, 3.0 rebounds and 1.4 assists in 12.5 minutes. That season (2018-19), he was voted to the Munich Tournament (ANGT) All-Tournament Team and the NIJT All-Tournament Team. Avdija's role expanded the following season, as he started 26 of 59 appearances, averaging 9.0 points, 4.7 rebounds and 2.0 assists in 21.7 minutes. As a result of his excellent play, he was given the Israeli BSL MVP. Avdija's best performance that season was June 21 in a win over Maccabi Ashdod, where he recorded 23 points (7-9 FG, 2-3 3Pt, 7-8 FT), seven rebounds, five assists, one steal and one block in just 24 minutes.