Ruaridh initially left Warriors in 2014 to join Wasps and later signed for Harlequins.
Talking about Ruaridh when he joined Glasgow as a full-time professional in May 2008, Glasgow coach Sean Lineen said: “I first noticed Ruaridh playing for Robert Gordon’s College at the Scottish Schools’ 7s at Murrayfield. He is yet to realise his full potential but I’m confident he’ll get there by being involved in a professional environment.”
He made his Scotland A debut in November 2008 as full back in the win against Georgia by 69-3 at Firhill, Glasgow. For his second Scotland A match, against the Irish three months later at the RDS, Dublin, he was in his favoured position at stand-off, scoring a conversion and a penalty goal. Two weeks later he was at inside centre in the 22-all draw with Italy in the A international at McDiarmid Park, Perth.
Three more Scotland A appearances followed in June 2009, when he scored 26 points in starting at stand-off in the wins against Russia and France A in the IRB Nations Cup success in Bucharest.
Ruaridh has played for Scotland at under-18 and under-19 levels as well as seven-a-sides.
He made his international sevens debut for Scotland in the opening tournament of the IRB's 2006-2007 world series in Dubai. He was in the squad also for the subsequent tournament in George (South Africa) and the series finale at Murrayfield. In October 2007 he was in the Rugby Ecosse Scotland squad in the Singapore sevens, and that was followed with selection for the IRB World Sevens Series tournaments in Dubai and George.
Under-18 international honours in 2005-2006 were followed up when he played in all five of Scotland's matches in the IRB Under 19 World Championship in Belfast in April 2007. Ruaridh represented Caledonia under-16 and North under-18 before being selected for the Scotland under-18 squad in season 2005-2006.
Playing for Robert Gordon's College, he kicked four conversions against Selkirk High School in the Royal Navy Schools Sevens final in 2006. In winning the competition with a 28-19 victory in that final, Robert Gordon's qualified to represent Scotland in the Four Nations Rugby Sevens in Portsmouth. Later in the year he made his first appearance in Glasgow Warriors' squad, selected on the bench for the European Challenge Cup match against Saracens at Watford, though he did not get on to the field.
Ruaridh also played a major part in helping the school 1st XV reach the final of the Bell Lawrie White Scottish Schools Cup in January 2006. After school rugby he joined the Cartha Queen's Park club in Glasgow, and in 2007 he switched to Glasgow Hawks.
Ruaridh, a member of Scottish Rugby's National Senior Academy, has played for Scotland also at cricket as a member of the national under-17 team.