[2] He began his career at Dunfermline Athletic in his native Scotland, and moved south of the border to join Leicester City in May 1965.
In January 1968, Sinclair joined Newcastle United, where he became a member of the team that won the 1969 Fairs Cup.
[3] In December 1969, he was sold to Sheffield Wednesday, where he spent three-and-a-half seasons before finishing his career back in Scotland with his former club Dunfermline, and lastly Stenhousemuir.
While at Leicester, Sinclair won his solitary cap for Scotland, appearing in a 1966 friendly match against Portugal.
He was the first member of Newcastle's Fairs Cup winning side to die.