He was selected for the New Zealand side for the second match against New South Wales in 1913, becoming Kiwi number 100.
The New Zealanders lost 58-19 and Finlayson, along with the other two debutants in the match, never played for NZ again after the loss.
[1] He joined the newly formed Petone club in 1912 after switching from rugby union.
In 1914 he joined the Hutt club but only played 4 matches for them before the team withdrew from the competition due to the enlistment of many players in the war effort.
Finlayson later played two first class games for Auckland, once against the touring Marylebone Cricket Club and once against Wellington in a 1931 Plunket Shield match.