Chelsea added to a woeful weekend draw away at struggling Newcastle with another lethargic and unorthodox performance against Porto at the Estadio do Dragao on Tuesday night.
Mourinho's recent headache was summarised by the exclusion of Nemanja Matic and last season's PFA Player of the Year Eden Hazard - two players far from the heights they both reached last season.
A somewhat surprise inclusion, though, was the incredibly out-of-form Branislav Ivanovic, who has repeatedly looked in danger against almost every side this season, with the general consensus being that Mourinho's preferred choice at right-back should be Cesar Azpilicueta.
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In essence, it was a frustrated and lacklustre Chelsea performance, with many of the Blues' starting team seen regularly punching the air in disgust or anger when things just didn't seem to click.
Porto never looked like losing the game, and in truth should have maybe scored more goals had it not been for another excellent solo display from Asmir Begovic in the Chelsea net.
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The game ended 2-1 to the Portuguese side, with strikers Vincent Aboubakar and winger Nacine Brahimi providing difficulties for Mourinho's defence throughout the game - Brahimi looking particularly potent and exciting.
Where has it gone wrong?
The loss raises questions as to how Mourinho should proceed from here: Does he drop all his senior players that are coming up short? Does he stick with a side now that has now under performed for almost a quarter of the season?
When Chelsea signed Spaniard Azpilicueta, little did we know he would have spent the majority of his career in London at left-back. The 26-year-old has nailed down his place in the starting Spain XI at right-back, and it remains a mystery why he still plays on the left for Mourinho.
Chelsea forked out just over £20 million for the talented Ghanaian left-back Baba Rahman, who is yet to play in the Premier League despite some impressive displays in Europe and the League Cup.
Once, twice, three times a failure
Diego Costa showed glimpses of his form from last season on Tuesday, but again he rarely caused the Porto defence any problems, and will now resume his Premier League suspension at the weekend.
Both Loic Remy and Radamel Falcao are struggling to register goals and rejuvenate their downhill careers, and it begs the question: Where will the goals come from for Chelsea?
Young Izzy Brown and Dominic Solanke, maybe? Both out on loan at Vitesse in Holland, though, so unless Mourinho can spark into life the aforementioned three front men, Chelsea will struggle for goals this season.
Chelsea's brightest star in midfield this year has been Brazilian Willian, and again on Tuesday night he was the pick of the bunch, scoring a magnificent free kick which left veteran Iker Casillas glued to the spot.
Hazard, Oscar, Cesc Fabregas, Nemanja Matic, Ramires? One word sums up these players this season - lackadaisical. All of the above have been run rings around all season, with the exception of the London derby win against Arsenal.
Porto found it so easy to play, with midfield general Giannelli Imbulo on top of his game, dictating the speed of play and allowing Aboubakar and Brahimi to cause problems in the final third.
How do Chelsea move forward?
It really is a trivia for Mourinho going into Saturday's evening kick off at Stamford Bridge against Southampton. Who does he maintain and who does he drop? We will soon see come Saturday.
One thing for sure is that things need to change if Chelsea are to reignite their title challenge as they currently sit eight points behind unprecedented leaders Manchester United.