The 21-year-old will link up with Scottish Premiership outfit, subject to international clearance. He spent last season on loan at Tony Bloom’s Belgian club Royale Union Saint-Gilloise.
David Weir said: “Alex had a really positive spell in Belgium last season and showed how well he can adapt to a different culture and club. He will get to work closely with Robbie Neilson, who was a full-back himself during his playing career and will have plenty of knowledge he can pass on to Alex. Myself and the loans team will be keeping a close eye on how Alex gets on over the next year and we wish him the best of luck.”