Due to an injury sustained in the 1940 preliminary final, he was unable to play in Melbourne's 1940 premiership.

He played (at half-back flank) in Melbourne's 1941 premiership side — as one of the team's best players, with a performance described as "outstanding".

[12] In 1942, Lock enlisted in the Australian Army to serve in World War II.

[13] He held the rank of corporal, served overseas in the 4th Field Ambulance, and was discharged on 4 January 1946.

[15] Barassi described Lock as someone who "combined strength with guile and football intelligence" and "was dashing and played with flair".