A rookie singing in 2017, Duman has emerged to be a crucial part of Fremantle’s backline at half-back. Duman played 14 games in 2019 and finished the season strongly with 21 disposals and 10 marks against Port Adelaide. Early in the year, Duman signed a two-year contract extension that will see him at Fremantle at least until the end of the 2021 season.