SUNDERLAND are confident of engineering a swap deal that will see Marcos Alonso complete a permanent move to the Stadium of Light while Modibo Diakite heads in the opposite direction to Fiorentina.

Alonso spent the second half of last season on Wearside on loan from the Serie A side, and the full-back is one of the players that Gustavo Poyet is especially keen to retain for next season.

The 23-year-old, who still has two years of his current contract to run, is valued at around £4m, but Sunderland are hoping to halve his price by offering Diakite as part of the deal.

Having failed to impress after joining the Black Cats as a free agent last summer, Diakite joined Fiorentina on loan in January and successfully established himself in the Italian club’s first team.

The centre-half would like to move to Florence permanently this summer, and Fiorentina’s desire to retain him should ensure that Alonso returns to Wearside to remain Sunderland’s first-choice left-back next season.

“If it were down to Diakite, he would stay with the Viola (Fiorentina) with his eyes closed,” said the defender’s agent, Ulisse Savini. “He gets on very well with both the coach and his team-mates, and Florence is a city that he likes very much.

“His value? It depends how highly Sunderland will value him. If they want to treat him as a possible starter, he will come at a cost. But if they treat him like he is surplus to requirements, he will command a much lower fee.”

As well as hoping to re-sign Alonso, Sunderland officials are also monitoring Bosnian left-back Gordan Bunoza, who will leave Polish side Wisla Krakow this summer.

Capable of playing at both full-back and centre-half, Bunoza will become a free agent next month, and Sunderland are set to tussle with Malaga, Palermo and FC Basle for his signature.

With Phil Bardsley, Ondrej Celustka and Diakite all expected to join Andrea Dossena and Carlos Cuellar in leaving Wearside, Poyet could have to sign up to four new defenders this summer.

He could also be welcoming Exeter youngster Matt Grimes to Wearside after Kevin Ball attended the Grecians’ final game of the League Two season at Hartlepool this month in order to watch the midfielder at first hand.

Grimes, who does not turn 19 until July, has made 37 senior appearances since breaking into Exeter’s first team at the start of the season.

It is looking increasingly unlikely that Fabio Borini will be returning to the Stadium of Light, with the Italian having featured in the Liverpool squad for last night’s friendly with Irish side Shamrock Rovers.

Brendan Rodgers is expected to include Borini in his squad for this summer’s pre-season matches, before making a decision on the forward’s long-term future in August.

Meanwhile, Craig Gardner has been informed that he will not be receiving a new contract with the Black Cats.

Gardner, whose current deal expires next month, has not started a Premier League game since early December and is expected to return to his native Midlands, with West Brom and newly-promoted Leicester City both interested in acquiring his services.