Career
Sinclair joined Southampton at the academy level at the age of eight years. On 1 September 2014, Sinclair joined Scottish Championship club Hibernian on a season-long loan. He returned to Southampton on 12 January.
On 30 June 2015, Southampton opted against offering Sinclair a new contract and therefore he was released with five other players including Jos Hooiveld, Artur Boruc, Cody Cropper, Omar Rowe and Chris Johns.
On 7 December 2015, Sinclair joined Southern Premier League side Frome Town. On 12 December 2015, Sinclair made his debut replacing Jake Jackson in the 60th minute in a 1–0 defeat to King"s Lynn Town.