Amateur career

He played rugby union for Sydney University.

He then moved to play for Drummoyne.

On moving to England, Keller first played for Guy's Hospital and then made use of his Scottish roots and played for London Scottish.

He played for Sheffield in 1950.^[2]

In 1952, he moved back to Australia. He returned to play for Drummoyne but retired mid season.

Provincial career

Keller was picked to play for the New South Wales Waratahs.

On becoming known on Scotland's radar in London, he was selected for the Anglo-Scots to play against the Provinces District on 11 December 1948.^[3]

Impressing in that match, Keller was then selected for the Blues Trial side in their match against the Whites Trial side on 18 December 1948.^[4]

He was then placed in the Scotland Probables side for the final trial against Scotland Possibles on 8 January 1949. The Possibles won the match, but should have been more comfortably ahead at half time. In the second half, a stack of positional changes made the match a lot closer, one of which was to put Keller on as a flanker, together with Douglas Elliot.^[5]

While at Sheffield, Keller played for Yorkshire, and captained the side.^[2]

International career

He was capped first for Australia in 1947, first as a prop but was then moved to flanker, and played 6 times in total for the Wallabies.^[6]

In the 1947-48 season, Keller played in 3 matches for Australia against Scottish districts:- North of Scotland, South of Scotland and Cities District, before playing against Scotland in November 1947.^{[citation needed]}

On moving to London and playing for London Scottish, he was then capped for Scotland in 1949, and played 7 times for the Scots.^[6]

Keller's nationality switch was not the only high-profile switch of the time. Ian Botting had made the move from the All Blacks to England. In 1950, the IRB voted to ban any oversea player from representing a Scottish, English, or Welsh national side, that had previously been capped by a British Commonwealth country; and this stymied Keller's future Scotland selection, as well as Botting's future England selection. The new rule did not preclude such a player switching nationalities once more to play for their first selected country, and Keller later returned to Australia.^[7]