Premier League side Sunderland are reportedly close to completing their second signing of the ongoing transfer window.
Earlier this month, manager Gus Poyet secured the services of full-back Marcos Alonso on a loan deal from Fiorentina.
Now Poyet is about to add Estudiantes defender Santiago Vergini to his ranks, according to Sky Sports News.
It is expected that the deal could be concluded either this evening or tomorrow morning.