Sky Sports News understands Sunderland have rejected a bid from Portsmouth for Nyron Nosworthy.
Skysports.com revealed earlier this week Portsmouth were one of a number of clubs chasing the former Gillingham stopper.
Portsmouth are in the market for defensive reinforcements with Sylvain Distin poised to join Everton and Nosworthy is seen as the ideal replacement.
Sunderland boss Steve Bruce is also in the market for a new defender having confirmed his interest in Hull City's Michael Turner, but it appears he is not keen to lose Nosworthy.
It remains to be seen if Portsmouth come back with a new improved offer for Nosworthy before the transfer window slams shut on Tuesday.