Sinyan played youth football for Oppsal IF and Holmlia SK, and also featured briefly in Holmlia's senior team before joining the junior ranks of larger club Lillestrøm.
In April 2016, Sinyan signed a two-year contract with Lillestrøm SK's senior team.[1] Sinyan featured in the first two rounds of both the 2015 and 2016 Norwegian Football Cups,[2][3][4] and made his league debut with substitute appearances against Sarpsborg 08 and Strømsgodset in July 2016.
After 2016 Sinyan suffered a long-time injury period, not making his comeback until September 2018 for Lillestrøm's B team.[5]
On 30 June 2020, Molde FK announced the signing of Sinyan on a three-year contract from Lillestrøm.[6]