The 3-1 home defeat to Southampton left Mourinho’s side in 16th place and trailing leaders Manchester City by ten points just eight games into the new campaign.
The defeat increased the pressure on the Blues manager, who insists he has no intention of walking away from Stamford Bridge.
But the Portuguese conceded his side’s most realistic target for the season is now to finish in the top four –- with top spot already looking beyond them –- and called for stability as the club goes through its most difficult spell in years.
Mourinho said: “Three months ago we were on the bus showing off the cups so I think it is time for all of us to be together now at the bottom of the league.
“And I think in December, January, February we are top four. To be champions would be very, very difficult.
“We are ten points from Manchester City and we could be 11 points behind Manchester United tomorrow. In football it is not impossible but it is very difficult.
“But top four is completely… not easy, but completely do-able.
“When you are in such a bad season after such a bad start, if you finish top four at the end of the season it’s because you kept a balance in a difficult season.
“So, for me, everything is clear. I cannot say more than this. I’ve been in football for a long time.”
Mourinho is confident he still has the backing of the Chelsea squad, but he admitted he understood the reaction of the home supporters who booed the decision to withdraw Willian midway through the second half.
The manager added: “Do the players trust me and feel I am the man for the job? This week we spoke about it and the answer was undoubtful.
“The supporters, when they booed today, the Willian decision, I’d have done the same as them if I didn’t know Willian was ill and vomiting in the dressing room at half-time.
“The doctor told me it would be difficult for him to carry on. The fans didn’t know what was going on.
“If they have some negative reaction, I’d do the same because the result wasn’t what we wanted.”
– no Matic humiliation –
Mourinho also insisted he had not intended to risk humiliating Nemanja Matic when he withdrew the midfielder just 28 minutes after introducing him as a half-time substitute.
He said: “It was not humiliating. I don’t do that to anyone in football or in life. It’s something that, if I do, I do without any intention. It was not the case.
“With the players, I live a situation that is not easy which is that I like them. I trust them. I know they are good players. But some of them are really in a difficult moment.
“Matic is one of them. He’s not playing well. He’s not sharp defensively and is making mistakes with the ball, not the best decisions.”
Willian put Chelsea ahead but Southampton leveled through Steven Davis and went on to claim victory through goals from Mane and Graziano Pelle.
Saints manager Ronald Koeman said: “It was a long time ago that we won an away game. This is one of the best players to get that first win away. But we have to keep working.
“We showed a great second half today, and it’s now an international break. We hope everyone comes back in good shape and we can try and play good football. That’s the key for us to win games.
“It was a difficult start this season, but the spirit of the team has stayed strong even after that difficult start. The changes needed time. Everyone understands that and, every week, we play better football.” – Agence France-Presse