 On 30 March 2017, following the resignation of Daniel Webb as manager of Leyton Orient, Riza was promoted from his role as assistant manager and placed in charge until the end of the 2016–17 season.In his first game as manager, on 1 April, Orient lost 0–2 to Wycombe Wanderers and Riza was sent to the stands for verbally abusing referee Charles Breakspear.On 22 April 2017, after losing to Crewe Alexandra, Orient were relegated to the National League, ending the club's 112 years in the Football League.