He was only 18 years and 6 months of age (i.e., under 21), but his parents gave formal permission to his enlisting and serving overseas.

[5] He served in France, returned to Australia on 2 January 1919, and was discharged on 2 March 1919.

A half-forward flanker, Rattray debuted for Fitzroy in 1917, but his progress was stalled when he missed the following season due to military service.

[6] Melbourne failed to make the Finals in 1924; and, consequently, Rattray was able to return to Fitzroy as a player for one Finals match, the second of the club's Round Robin Semi-Final matches against Richmond on 20 September 1924.

He left Fitzroy after the 1924 season, and, having been originally chosen to be the playing−coach of North Melbourne in its inaugural VFL season,[7] he was granted a clearance to serve as the captain-coach of Brighton in the Victorian Football Association (VFA).