Sources have confirmed to HITC Sport that they believe the Dutch international is going elsewhere.
HITC Sport has been told by sources close to the Black Cats that they do not see their offer for De Guzman being successful.
The 27-year-old spent two very good seasons on-loan at Swansea City before he was snapped up by Napoli last summer, but now he is available to head for pastures new and Sunderland made their move.
Sunderland made an offer to loan him for the season as Dick Advocaat had hoped he could lure De Guzman back to the Premier League, but it now appears he is going elsewhere.
De Guzman previously made 95 appearances for Swansea spread across two campaigns, netting 16 goals and helping the Welsh outfit to League Cup glory in 2012/13.