His relatively late rise to prominence can be explained by his service during the First World War with the Royal Army Medical Corps and a subsequent serious injury he received while serving in France.
The following season Collins provided cover for regular goalkeeper Charlie Shaw, making his Scottish League debut in a 4–0 win against Dumbarton on 6 September 1921.
At the end of the season however, Celtic made Collins available for transfer, and he returned to Jacobs to play in the newly formed League of Ireland.
When Collins began his international career in 1922, Ireland was represented by a single team, selected by the Belfast-based Irish Football Association.
His teammates that day included, among others, Ed Brookes, Paddy Duncan, Tommy Muldoon, Charlie Dowdall and Johnny Murray.
The FAI XI lost the friendly 2–1 and Collins was blamed for conceding a soft second goal, allowing a poorly hit shot from 20 yards to slip under his body.