José Mourinho has publicly questioned his players' attitude and accused them of complacency during Saturday's defeat at Newcastle United. The Chelsea manager has warned the squad they must now recapture the effort and industry which propelled them to six successive wins through October as he seeks an immediate response against Schalke.

The German side, beaten comfortably in Gelsenkirchen a fortnight ago, visit Stamford Bridge on Wednesday with Mourinho and his staff still digesting the rather aimless display on Tyneside. Mourinho had sensed his players lacked focus during the first half at St James' Park and attempted to shrug them out of their lethargy at the interval. Yet the performance continued to splutter thereafter, the visitors were beaten 2-0 and the result set alarm bells ringing in light of Chelsea's relatively wretched record at this stage of the year in recent seasons.

The team have suffered awkward periods, sometimes prolonged, under seven different managers at this stage of the season over the last seven years, with a slump in form as winter sets in something of an annual event these days. Mourinho has been dismissive of his team enduring similar problems, but his frustration at the display at Newcastle was clear. "My bad reaction with the players was not after the game, it was at half-time," Mourinho said. "I was feeling [their] mentality was not the best. But sometimes, when you win a lot of times, players forget why they win. When you win four or five matches in a row, you forget why you won and think it was just because you are good. But there are many other ingredients in football that make you a consistent winner. You cannot think you win because you have a nice shirt or are in a good run or a lucky moment. If you think like that, you're in trouble.

"Maybe I was also influenced by the way they grew up so fast as a team. They coped very, very well with the pressure we put on ourselves in the Champions League [after losing at home to Basel in the opening fixture], winning six crucial points away. They have put in great performances: they showed good personality to play a very difficult match against [Manchester] City; good personality to go to Arsenal without many of the players who normally are playing and have the personality not just to win but be so dominant. So maybe I was also caught by surprise."

Mourinho added: "The only difference is during the first half [against Newcastle] it looked like they were not feeling it and I was feeling it. At half-time I was telling them they were competing more in training sessions than in that game. They were playing as if the goal would arrive, thinking: 'We don't need to push, to be intense or aggressive. It'll arrive.' I said maybe yes, maybe not. But if you're in that dynamic, it's difficult to change. You try and wake them up at half-time but the problem was the attitude. I was disappointed. I want my team to be proactive, not reactive. Things happened I didn't like. I want my team to be better."

Mourinho had suggested after that defeat that he had made "11 mistakes" in his selection, implying there would be sweeping changes for the re-match with Schalke as Chelsea seek to take a grip on Group E. "I said 11 and, of course, I was exaggerating because some of the players put in good, normal performances," he said. "It's not about changing 11 and I don't want you to see the changes I make against Schalke as somebody paying for the defeat against Newcastle. That's not the case. A football player is a human being and human beings make mistakes. Sometimes they don't have the best approach.

"Maybe the worst thing that happened to us in Newcastle was the easy start. You go there and see lots of space, you play easily and they don't press you, as if they were a bit scared of us. We hit the post twice and were dominant. If we'd been in trouble, and the team had felt that, the reaction might have been different. But you play big matches before that and you know you have to be at the top of your level. You are at the top of your concentration. Suddenly you get a match where you become a little bit complacent. It's the mistake not just of football players, but human-beings."

Chelsea will be without Fernando Torres for the game at Stamford Bridge, as well as Saturday's visit of West Bromwich Albion, after he damaged his thigh in training on Monday. He underwent treatment at Cobham while Mourinho put the first-team squad through their paces and the club's medical department will scrutinise scan results on Wednesday. Ryan Bertrand succumbed to a knee injury in that session and has also been ruled out and the manager is considering recalling Gary Cahill, César Azpilicueta and Mikel John Obi.

Samuel Eto'o and Demba Ba will fill in for Torres. "They have been waiting for opportunities to play so, when they have their chance, they know it's in their hands," added Mourinho. "That has to be a good motivation for them. Hopefully they can express on the pitch the way they work during the week. But this game will not be easy. Schalke's away record is very good, and they are a very physical team, which we are not. I don't know if they come here to win the game, thinking still about topping the group, or to get a point and be very defensive, to try and qualify with the other two matches they have. We have to be ready for both things. But they are a difficult opponent and the result in Germany means nothing."