Rotherham first came to note as a rugby player when he represented Cambridge University, winning two sporting Blues in the Varsity matches of 1890 and 1891. Soon after, Rotherham is recorded as playing for Richmond, then during the 1890/91 season he was picked for the invitational tourists, the Barbarians. In 1891 Rotherham was selected to join Bill Maclagan's British Isles team on their tour of South Africa. Rotherham played in two Tests, the first at Port Elizabeth, paired at half back with William Wotherspoon and the final test in Cape Town, this time partnered with Howard Marshall. Both Tests resulted in wins for the tourists and saw Rotherham score with conversions in each of his appearances; making him the tour's top Test scorer.