Rangers reportedly hold a "strong" interest in Levski Sofia defender Jose Cordoba as he approaches the final 12 months of his contract.
The Panama international is in-demand this summer according to reports in his homeland, with Philippe Clement's side said to be among the chasing pack as they look to strengthen the heart of the backline for next season.
Leon Balogun is out of contract this summer while Ben Davies has struggled to impress since the arrival of the Belgian after being hampered by injury.
Connor Goldson struggled for form before injury brought an end to his season and is on Al-Ettifaq's wishlist this summer. John Souttar has been the mainstay of the backline for the title run-in – and it appears Clement and director of football Nils Koppen are keen to add to the centre-back options this summer.