Amateur career

Robertson played rugby for London Scottish.^[2][3][4]

He was made captain of the club for season 1914–15, but the First World War intervened and his captaincy was then never displayed on the pitch.^[5]

Provincial career

He played for the Anglo-Scots against the Combined Scottish Districts side on 23 December 1911.^[6]

He played for the Whites Trial side against the Blues Trial side on 6 January 1912, while with London Scottish.^[3]

He was selected to play for London Counties against South Africa in their European tour, along with fellow Scotland players Lewis Robertson, Walter Michael Dickson and Charlie Usher,^[7] however Dickson did not play and his place was taken by another Scotland player William Purves.^[8] South Africa won the match 12 - 8.

The same 4 Scotland internationals that played the match were invited to play for London Counties in a return match against South Africa on 16 November 1912. However at this point the London clubs were getting frustrated by the number of representative matches their players had to face and the Scotland internationals thus took a stand and declined that invitation.

The Scottish Referee newspaper of 18 November 1912 noted:^[9]

A LONDON-SCOTTISH PROTEST. Trouble has been brewing for some time in Metropolitan Rugby circles (says the Sporting Life) and the action of the London Scottish forwards declining to play for London Counties against the South Africans is calculated to bring it to a head. The London clubs, with all their loyalty to the Union, have resented the introduction of so many representative matches at headquarters on Saturdays. Not without reason do they contend that the Springboks' fixtures might reasonably have been arranged for the mid-week, when they would not have clashed with the club games. For Saturday's match four of the London Scottish forwards —L. Robertson, R. D. Robertson, C. Usher, and W. D. C. L. Purves, all internationalists — were invited to play for London. They declined the honour by way of a protest. The London Scottish committee left their players free choice in the matter, though holding the opinion that the time has come when London club football should insist on more consideration in the matter of club fixtures. In their stand they have made they have the sympathy of practically all the Metropolitan Rugby clubs. Interviewed by a press representative; Mr. R. D. Robertson, the hon. secretary of the London Scottish club, said the action of the Scottish forwards in declining to play against the South Africans was in the first place due to their desire to play for their club against the Harlequins, and also as a protest against playing so many matches of a similar nature on Saturday at the expense of London club football.

International career

He was to play in only 1 international match, which was against France in 1912.^[10] He was not originally selected to play, but due to his London Scottish teammate Lewis Robertson who was originally selected for Scotland being unable to play in the match due to the death of his father, Robert was then drafted in as a replacement.^[11][12][13]

Administrative career

As noted above, Robertson became the Honorary Secretary of the London Scottish club.^[9] He proposed that Duggie Lyall Grant succeed him in office in 1913.^[5]