Vergini, 25, was on loan at Argentina Primera Division team Estudientes from Uruguayan parent club Atletico Felix but will now team up with Gus Poyet's team until the end of the 2013/14 Barclays Premier League campaign.

The centre-back started his career in Paraguay before joining Italian side Verona in 2011 and has since represented Argentina at the highest level.

Vergini is the second defender to move to Wearside in January after Marcos Alonso joined on loan from Fiorentina. Vergini will be avalable for Sunderland's next Barclays Premier League match, at home to Stoke City on Wednesday 29 January.