His first stint with Melbourne was in the 1906 VFL season and he kicked three goals in his debut, the first of five games he played that year.

[3] His roving was good enough to earn him a spot in the VFL representative team which competed against South Australia in 1913.

[4] He played 30 games for the club and in 1914 represented Western Australia five times at the 1914 Sydney Carnival,[2] where he won a medal for the "Best stab passing".

[5] In World War I, Tomkins joined the 28th Battalion in the Australian Imperial Forces and fought on the Western Front, where he was badly injured in an artillery barrage during the Battle of the Somme.

Hit by a trench mortar, he received 13 wounds in the explosion, to his right leg, abdomen, right arm and left wrist.