The 29-year-old was substituted after just 11 minutes of the Blues' 4-0 Champions League victory over Steaua Bucuresti with a knee concern, and is now almost certain to miss his country's matches against Belarus and Georgia next week.
He was already unavailable for Chelsea's Premier League meeting with Norwich City on Saturday due to suspension, and thus Mourinho has identified their trip to Cardiff City after the international break as the game in which Torres is likely to make his return.
"The doctor is very confident it's not a big injury, like we had with Marco van Ginkel," Mourinho told reporters. "It's something in his knee, his ligament, and we have to wait for the scan.
"He knows that he doesn't play against Norwich on Sunday. He knows that he cannot go to the national team. He knows he has 15 days until the next match he can play, which is against Cardiff. Let's see the scan. If the injury is an injury for 15 days, I think he'll be fine. That's okay.
"The problem is if it's more time and it's a pity for the guy, because he's in a very good moment. He played fantastic against Tottenham. Today he started the game because he deserved to start the game. It's a pity, but that's football."