The left-sided star has established himself as a fans' favourite since signing for £3.5 million from Argentinos Juniors in July 2000.
Black Cats boss Mick McCarthy sees the South American as an integral part of his plans to try and take the club back into The Premiership and so has instructed officials at the club to begin negotiations to tie him to Wearside for longer.
In other news, Stockport's highly-rated goalkeeper James Spencer has been training with the Stadium of Light outfit trying to impress.
