Scottish winger Robertson won the Scottish championship with Hearts in 1897 where he was instrumental in clinching the title by scoring four times in a 5-0 victory over Clyde on 20 February 1897. Four days after Robertson played his only international for Scotland the Edinburgh club suffered as teammates Robertson and John Walker both moved to Liverpool. The Evening Telegraph revealed in 1902 how Robertson came to Hearts' attention. "The Tynecastle Club was engaged a Fauldhouse in a second eleven cup tie, and being a man short the officials were forced to search for a substitute, and Robertson was picked from among the spectators as being, according to local reputation, “a likely hand.” He performed so satisfactorily that right away he stepped into the Hearts regular team, so that it may be said he was a born player." Robertson scored on his Liverpool debut against Sheffield Wednesday and only missed a single League match over the next two seasons and contributed 15 League goals, a terrific total from a man in his position. In 1900/01 he was again ever-present, scoring nine goals as Liverpool won the first division title for the first time. Northern Athletic Football Guide claimed Robertson was "fast, every clever with the ball, and ‘class’ writ large in every movement." Robertson added 25 games and six goals to his League and cup totals in 1901/02, but his play wasn't as effective as in years gone by according to the Lancashire Evening Post in February 1902. "Robertson still skips along quickly, and executes some charming footwork, but there is lacking just that little bit of something “extra” – especially in shooting – which aforetime raised him well above the level even of good outside wingers, and he is not now blessed with the “devil,” say of the other Liverpool extremist, Cox." Robertson returned to Scotland to play once again for Hearts. He made three second division appearances for Manchester United in the 1903/04 season.