He collected all-tournament team honours after leading the event with 24.7 points and 12 rebounds per game with a PIR of 29.7, while ranking second with 6.7 assists per game. Professional career Maccabi Tel Aviv (2017–2020) On 5 November 2017, Avdija started his professional career with Israeli club Maccabi Tel Aviv, signing a six-year deal with the club. On 19 November, he made his professional debut in the 2017–18 Israeli Basketball Premier League, playing three minutes against Ironi Nes Ziona. At 16 years and 320 days of age, he became the youngest player to ever play for his club's senior team. Avdija made his EuroLeague debut on 22 November 2018, at the age of 17, in a 74–70 loss to Fenerbahçe. He scored two points in three minutes of playing time. On 24 October 2019, at the age of 18, Avdija made his first start in the EuroLeague, recording six points and three rebounds in 16 minutes in a 76–63 victory over Valencia. On 11 January 2020, Avdija recorded a then career-high of 22 points, shooting 9-of-15 from the field, with five assists in a 94–83 win over Hapoel Holon. On 31 January, Avdija was named Israeli Player of the Month in the Israeli Basketball Premier League after averaging 14.5 points, 5.3 rebounds, and 2.5 assists per game, with an 18.3 PIR, in four games played that month. On 1 February, Avdija established a new career-high of 26 points, shooting 9-of-12 from the field, and grabbed six rebounds in an 86–81 loss to Hapoel Eilat. Six days later, he scored 13 points, including eight in the second quarter, in a 78–77 victory over Fenerbahçe. His dunk over Luigi Datome during the game would be named EuroLeague Magic Moment of the Season in July 2020. On 16 April, Avdija declared for the 2020 NBA draft. Avdija's season was suspended for about three months due to the COVID-19 pandemic. He returned to action on 21 June, recording 23 points, seven rebounds, and five assists in 24 minutes in a 114–82 win over Maccabi Ashdod. On 23 July, he scored 22 points, including 10 in the fourth quarter, and grabbed 10 rebounds in an 83–68 win over Hapoel Tel Aviv, helping Maccabi Tel Aviv advance to the Israeli Basketball Premier League Final Four. In the Final on 28 July, Avdija recorded five points, seven rebounds, four assists, and two steals to help Maccabi