Russell returned to Glasgow for the 2013/14 season. With Glasgow's top players away on international duty for the 2013 Six Nations Championship, Russell was named on the bench to face Zebre on 10 February 2013 as part of the 2012–13 Pro12 season, coming onto the field and making his professional debut at the 56th minute of the game. During the 2013–14 Pro12 season, Russell made his first start at the club, starting at Inside Centre against the Newport Gwent Dragons at Scotstoun Stadium on 22 November 2013. Glasgow Warriors Head Coach Gregor Townsend offered Russell a full-time contract with the club that began in the 2014–15 season.