The Spain international was absent from the squad that beat Crystal Palace 2-1 on Saturday and will remain on the treatment table for a while longer.
And after the match Mourinho confirmed he is not sure when Costa will be fit to return for Chelsea, though he sarcastically remarked that he is sure the striker will be fit for Spain's next match.
"The only thing I can say is after Arsenal he went to national team, he played two big matches against Slovakia and Luxembourg and become in condition where he's not able to play for this club," Mourinho told reporters.
When asked if he had spoken to the Spain medics, Mourinho added: "For what? To spend money on the call?
"I think he'll be in great condition in mid-November to be back for the national team. That's for sure. Our medical department will take good care of him and he'll be in perfect condition.
"He will play for me when he's got free time from the national team."