Sunderland have reportedly lodged an offer to Fiorentina for their left-back Marcos Alonso.
The Spaniard spent the final six months of last season on loan at the Stadium of Light, but he has since returned to his Italian employers.
However, Black Cats boss Gus Poyet would like to be reunited with the 23-year-old and he has attempted to make that happen with a formal bid for his services, according to Sky Sports News.
Alonso joined La Viola from Bolton Wanderers last summer, but he struggled to hold down a regular place in the starting lineup.
