According to reports in South America, the Black Cats have already made one offer for the player which was rejected by his club.
Beginning his career at River Plate, the 24-year-old made almost a dozen appearances for Los Millonarios, before joining current club Tigre on loan in 2011.
Completing a permanent transfer a year later, Orban is able to play at both centre back or left back and is believed to have a £2.5million release clause for clubs in Europe.