Sunderland Transfers: 5 Players Black Cats Should Sign Before Transfer Window Shuts

5. Marcos Alonso (Fiorentina)

24 year-old Alonso impressed during a loan spell on Wearside in 2014, and many Sunderland fans called for the Spaniard to be signed up permanently. A deal never materialised for the left-back, and he has remained at Fiorentina since. Though Sunderland have Patrick van Aanholt, there are no other natural left-backs in the squad to either compete with the Dutchman or to provide backup. Alonso wouldn't command a monumental fee, and has already proven he can cut it in England with both Bolton Wanderers and Sunderland. If van Aanholt's opening day defensive display against Leicester was anything to go by, the Wearside club may need a quality left-back to compete for a starting place sooner rather than later.