He played as a forward for Hawick.[2][3]
The former commentator Bill McLaren mentions Foster as one of the Hawick greats that he grew up with:
"I was brought up on stories of the great Scottish players of the twenties, many of whom I never saw play but knew all about... I used to go with my father to see matches at a very early age, the great Hawick heroes including Willie Welsh, Jock Beattie and Jerry Foster, so I had an all-consuming desire to wear the green jersey of Hawick."[4]
He represented South against the North of Scotland on 19 November 1932.[5]
Foster was capped by Scotland four times.
He made his debut against Wales in the Five Nations match at Murrayfield Stadium on 1 February 1930.[6]
His last match was the Home Nations match against England at Twickenham on 19 March 1932.[7]