It was announced in November 2011 that Gray would be leaving Glasgow Warriors at the end of the 2011–12 season, having agreed to sign for the Sale Sharks.

It was announced on 16 January 2020 that Gray would be returning to his original Glaswegian club, Glasgow Warriors, on a two-year deal from the 2020–21 season.

A former Kelvinside Academy student, Gray has represented Scotland at every age group from under-17 through to the senior sides, winning his first cap as an international as a substitute in the 2010 Six Nations Championship match against France.

[6] He scored his first international try in a Six Nations game against Ireland in March 2012, where he smashed through Tommy Bowe and dummied a great pass against Rob Kearney.

Gray's 2013 Six Nations got off to a good start with Scotland beating Italy and Ireland, but during the match against Wales at Murrayfield, Edinburgh, he was injured and taken off the field.