Gray made his debut against Ulster in the closing stages of the 2008/09 season and went on to make 47 appearances during his first spell with the Warriors.
Gray was named in the PRO12 Dream Team for the 2010/11 season following his displays in the Glasgow engine room, before agreeing to join Sale Sharks at the end of the 2011/12 campaign.
He then made the switch to France after a single season with the English outfit, spending three seasons with Castres before a four-year spell at Toulouse that included a Top14 title.
Along with younger sibling Jonny, Gray is part of the 21st set of brothers to play together for Scotland - his international debut against France in 2010 marked the beginning of an illustrious international career, with his 50th cap arriving in the 2015 Rugby World Cup clash with South Africa at St James' Park in Newcastle.
To date, he remains the most recent Scottish player to earn a Test cap for the British and Irish Lions, coming off the bench in 2013's decisive third Test victory over Australia.