The well-travelled 37-year-old played for the Goldenacre club before embarking on a professional career that took in spells with Harlequins, Borders Reivers, Scarlets, Montpellier, Worcester Warriors, Bristol and Newport Gwent Dragons.
Douglas then spent a season as a player/coach in Welsh club rugby with Cardiff before calling time on his playing career in 2015 having spent 17 tears in the professional game. He made 43 international appearances.
He is now working in the Capital with a recruitment company, and has been involved at Heriot’s in a business capacity.
Douglas will work with head coach Phil Smith and will replace his fellow ex-international player, Steve Lawrie, who has moved across the city to take the reins at Watsonians following a successful spell at Goldenacre, the highlight of which was a treble success of BT Premiership, Cup and Charity Shield last season.