And once more the managerial juggling will begin.
Mourinho is accustomed to having to keep big squads happy, although not even his man-management skills can get it right every time.
Last season at Real Madrid, for instance, he took the club to its third Champions League semi-final in a row but on the way fell out with Sergio Ramos and club captain Iker Casillas and towards the end of his reign in Spain his relationship with Cristiano Ronaldo also became fraught.
At Chelsea right now all is amicable, but how long can that last when in midfield alone Mourinho has mercurial talents such as Eden Hazard, Juan Mata, Oscar, Andre Schurrle, Frank Lampard and Willian to choose from?
Who does he leave out? How does he prioritise who should play in the Premier League and the Champions League? Mourinho has a refreshingly honest template for dealing with such problems.
"I don't know if I keep them happy," he said. "I'm happy because I have so many good players and I'm happy because doing well or wrong I do it in an honest way.
"I will judge on the pitch. I will not judge on words or interviews, not on agents or parents or friends or comments or the press or twitters or something like that.
"I will let football speak and I will let football decide.
"So if one guy is the man of the match he has to play the next match."
It is a simple philosophy and one which players cannot easily grumble about.
There is no doubt Mourinho has inherited and added to a squad which currently looks like having the strength in depth to mount a twin-pronged attack on both the Premier League title and the Champions League trophy.
On Wednesday night against Basle, Chelsea must be organised and solid but should be too powerful for a side they beat in the semi-final of the Europa League in May.
Under the guidance of Rafael Benitez, Chelsea won the first leg in Switzerland 2-1 and then finished off the job with a 3-1 victory at Stamford Bridge, although they did suffer a few moments of anxiety when they allowed Basle to score first in the second leg through Mohamed Salah.
Fernando Torres, Victor Moses and a trademark 25-yard thunderbolt from David Luiz eventually wrapped things up.
Mourinho will demand a more ruthless job this time at home to a side who caused something of a stir in 2011-2012 when they drew away with Benfica, then drew 3-3 with Manchester United at Old Trafford before stunning United 2-1 in Switzerland to progress to the knockout phase of the competition.
They carry a modicum of danger as do Schalke and Steaua Bucharest, who are also on the menu in Chelsea's group, but none of them have the stunning array of talent which now resides at Stamford Bridge and which Mourinho is content to see through to the end of the season.
In fact, he is looking forward to not having do any more transfer business this season.
"My squad is very good with solutions in every position and a great balance between the experienced and the young boys," said Mourinho.
"I will be happy if in January nothing happens with us. I spoke with the final group and I told them that I wish that in January everybody is happy and nobody wants to leave.
"I am happy with everybody and I don't want anyone to come in. That's what I want for January and that would be the perfect situation for us."
If that is the case, it might also mean Chelsea were closing in on another European trophy.