County have suffered a major injury blow just hours before their Coca-Cola Championship trip to Hull City.
Striker Mounir el Hamdaoui has suffered a shoulder injury that could end his loan spell with the Rams.
He picked up the problem during the first-half of Tuesday's 1-1 draw at Wolverhampton Wanderers and although he fought on to score Derby's second-half equaliser, the injury is more serious than first feared.
"At the game on Tuesday his shoulder did pop out and pop back in again in the first half, and he complained about the pain at half-time," Rams boss Phil Brown confirmed to www.dcfc.co.uk
"He's just starting to fire on all cylinders at the moment as well with two goals in three games, so now it's a case of hoping that one of the other strikers will step up to the plate with that sort of form.
"We've spoken with the medical people at Tottenham and they've said that if it is going to be a long-term injury then he would need to go back there, and they would deal with it.
"He is on his way back down to Spurs but if there's a positive update then hopefully he will come back if possible.
"Mounir is staring at a possible operation and if that's the case then he will be looking at around two or three months out, which will end the loan deal."