Derby remain in contract talks with goalkeeper Kelle Roos, but are likely to face competition for his services, according to Sky sources.
The 26-year-old only made his league debut for the Rams in January, five years after joining the club from non-league Nuneaton Town.
Roos has since featured 13 times in all competitions for Frank Lampard’s side, keeping five clean sheets, helping them maintain a push for the play-offs.
His contract expires at the end of the season, with Derby keen to secure him to a new long-term deal rather than risk losing him on a free transfer.
But Sky sources understand Bristol City, Hull and Stoke are among the clubs keeping tabs on his situation, as are a number of sides in Roos’ native Netherlands.
Since arriving at Derby in January 2014, Roos has spent spells on loan at Rotherham, AFC Wimbledon, Bristol Rovers, Port Vale and Plymouth.