The Black Cats signed the former France international from Tottenham Hotspur last summer, following two spells at White Hart Lane.
He made 23 appearances last season as the Wearside outfit staved off relegation and also started Sunderland’s first fixture of the current campaign – a 2-1 defeat to Pep Guardiola’s Manchester City.
Kaboul finished the full 90 minutes with four successful aerial duels and 13 clearances to his name, the latter statistic being the most of any player for either side.
But French publication L’Equipe suggest the 30-year-old is set to make an abrupt exit from the Stadium of Light.
They claim fellow Premier League outfit Watford are close to reaching an agreement with Sunderland over the 6 foot 4 centre-back’s transfer fee.
David Moyes is by no means short of potential replacements. In addition to insisting Lamine Kone will be handed a new contract, the Scot has signed Papy Djilobodji and Paddy McNair.