Everton striker Dominic Calvert-Lewin is out of the Merseyside derby against Liverpool on December 1.
Calvert-Lewin started the season by scoring three goals in Everton's first three games but he has not played since August 26.
It was hoped he would be back before the international break but he suffered a setback in training, and his rehabilitation from an issue with his quad has been slow.
Blues manager Rafa Benitez made it clear that England forward Calvert-Lewin would not be coming to his rescue any time soon.
"I try to not put dates out because you never know, but I said at least two or three weeks," Benitez explained.
"What does that mean? It depends on how he progresses. It could be sooner or later.
"What I can say for sure is that he will be out for two or three weeks minimum."