Damien Duff made a goalscoring return for Newcastle in a friendly victory over Middlesbrough on Tuesday, but manager Sam Allardyce does not believe the winger will be ready to face Derby.
Duff has yet to feature for Newcastle's first-team this season after suffering a dislocation in the middle of his foot against Portsmouth back in April.
The Republic of Ireland international is now thought to be close to a return to action after netting in Newcastle's 4-1 defeat to Boro, but Allardyce does not believe he will be available this weekend.
"Damien played another 90 minutes and is getting stronger, but I don't think he will be involved at all against Derby at the weekend," Allardyce told the Northern Echo.
Meanwhile, Allardyce has confirmed that star striker Michael Owen is not expected to return to training until the end of the week.
Allardyce had previously hoped Owen - who has been sidelined with a thigh injury sustained in England's friendly victory over Austria in November - would be fit to face the Rams, but he has now said the 28-year-old will not figure.
"A number of players featured in the game, but Michael Owen was not one of them," added Allardyce.
"The thigh strain has taken a little longer than we thought to heal and he won't be back in training until the end of the week.
"We'd hoped he would be able to play in the practice match and then against Derby, but we'll just have to be patient with him."
However, Steven Taylor, Abdoulaye Faye and Shola Ameobi were all able to build up their fitness levels as they recover from injuries.
"Everyone who played has come through it fine," Allardyce continued.
"Abdoulaye Faye and Shola Ameobi also played, but Steven Taylor is the only one who is likely to come back into the team for the Derby game."