A hard-tackling full-back, Reg Thomas acted as cover for the regular right-back, Bill Adams, throughout his career at The Dell. His stay encompassed four years and, after playing eight consecutive League games in the latter part of 1931-32 his appearances after that were confined to the Reserves.

In December 1932 Reg broke his leg in a friendly against Poole, which effectively finished his professional career

although he hung around another season to feature in 26 Reserve games. He then decided to give up the professional game to join the Metropolitan Police Force the following May. In the 1939 mini census Jim was listed as a PC based in St Pancreas.