New boss David Moyes has lost his opening two Premier League games in charge of the Black Cats and is desperate to add to his squad before the transfer window opens.
Now he is on the verge of bringing in 28-year-old defensive midfielder Iborra, who he knows well from his time in Spain managing Real Sociedad.
Iborra has made 83 appearances for Sevilla, scoring 17 goals, since moving from Levante in 2013.
The Spaniard was linked with a move to West Brom last season and is keen to play in the Premier League.