Thomas (Tommy) Sinclair was born in Shettleston. In 1938 he joined Bolton Wanderers. An inside-right, he scored 5 goals in ten games in the 1938-39 season. During this period the team included Harry Goslin, Jackie Roberts, Jack Hurst, George Hunt, Albert Geldard, Harry Hubbick, Don Howe, Ray Westwood, Jack Atkinson, Tom Woodward and George Eastham.
On 15th March, 1939, Adolf Hitler ordered the German Army to invade Czechoslovakia. It seemed that war was inevitable. On 8th April, Bolton Wanderers played a home game against Sunderland. Before the game started, Harry Goslin, the team captain, spoke to the crowd: "We are facing a national emergency. But this danger can be met, if everybody keeps a cool head, and knows what to do. This is something you can't leave to the other fellow, everybody has a share to do."
Of the 35 players on the staff of Bolton Wanderers, 32 joined the armed services and the other three went into the coal mines and munitions. This included Harry Hubbick, who resumed his career down the pits and Jack Atkinson and George Hunt served in the local police force. A total of 17 players, including Tommy Sinclair, Harry Goslin, Danny Winter, Billy Ithell, Albert Geldard, Don Howe, Ray Westwood, Ernie Forrest, Jackie Roberts, Jack Hurst and Stan Hanson, joined the 53rd (Bolton) Field Regiment.