On the loss to Real Madrid in the Champions League, which was marred by an alleged racist attack on Vinicius Junior by Benfica's Gianluca Prestianni, Mourinho said: "That game was extremely demanding in every aspect.
"Up to the 50th minute, it required maximum physical effort and concentration, but I also have to admit that from then until now - and it’s not over yet - it hasn’t been easy to handle everything emotionally, all that happened and keeps happening.
"But we have a game tomorrow, crucial for our ambitions, where winning is essential. We need to stay focused and play at our best."
Looking ahead to Benfica's next league match against AFS, he added: "We expect a team similar to the one that played against Estoril and fought for nearly 120 minutes to reach the Portuguese Cup semi-finals.
"I believe Joao Henriques has improved the team; they’re defensively organised and have always had dangerous players on the break. Like everyone else, they’ll come to Estadio da Luz to defend a lot and try their luck on counter-attacks.
"If we want to keep looking up at Sporting and FC Porto, and not down at Gil Vicente and SC Braga, we have to win this match."
On Prestianni, who is suspended for the AFS game, and his squad options, Mourinho added: "We’ll make some adjustments.
"I can say without hesitation that Fredrik Aursnes will have to sit out so he can have a chance to play in Madrid; he’s not in any condition to play right now. We’ll make changes, but always with the awareness that it’s a tough game and we need to win it."