The striker suffered a calf injury last week while training with John Toshack's national side and is expected to be out for around four weeks.
Reds boss Billy Davies will hope that another Wales player Chris Gunter will return from international duty unscathed. The right-back played both his country's World Cup qualifying games, in Finland at the weekend and in Liechtenstein on Wednesday night.
On-loan midfielder Radoslaw Majewski, meanwhile, reported back with a clean bill of health after representing Poland's Under-23 side.
Forest will again be without defenders Julian Bennett and James Perch (shin), although the latter has resumed training.
The game sees the return to the City Ground of former Forest boss Colin Calderwood, who is assisting Newcastle's caretaker manager Chris Hughton.