Watford are increasingly confident of signing Younès Kaboul after a bid of around £4m was accepted by Sunderland. David Moyes gave the former Tottenham centre‑half permission to discuss terms after learning of his desire to return to the London area for personal reasons.

Signed for £5m last summer, Kaboul initially struggled at the Stadium of Light but subsequently emerged as a key player once Sam Allardyce took over as manager. The 30-year-old formed a strong defensive partnership with his fellow Frenchman Lamine Koné – admired by Everton – and the pair proved a principal reason why Sunderland managed to escape relegation in May. In an attempt to thwart Everton, Koné has now been offered a lucrative new contract which he is scheduled to sign on 1 September.

Moyes, Allardyce’s successor, had hoped to keep Kaboul but now could reinvest the money made by selling him to Walter Mazzarri’s side instead. Kaboul is understood to have been offered a three-year contract at Vicarage Road.

“This is not an easy situation for me, but the club and the manager have shown an understanding of my personal circumstances and I am grateful for that,” Kaboul said in a statement released by his current employers.

“The Sunderland fans have supported me fantastically well since I came to the club, they gave me my passion back and I sincerely thank them for that. I hope they understand that I have made this incredibly difficult decision for me.”

The Chelsea defender Matt Miazga, meanwhile, has been offered to Sunderland on a season-long loan.