"Chelsea have the best coach in the world" was the assessment of former Blues midfielder Deco this week.
The ex-Portuguese international was talking to Chelsea TV, per Daily Star, in the aftermath of Chelsea's 2-0 victory over Paris Saint-Germain that saw them reach a seventh Champions League semi-final in 11 years.
The result on Tuesday night was a timely reminder as to the qualities this team has. Just like Deco's own sentiments, it reminded us of the genius of the Blues manager.
Mourinho is many things in the media—a purveyor of mind games, a rent-a-quote jester for headlines and sometimes even an enemy of football.
It's not often his tactical nous is mentioned these days. The impact of his celebrity seems to have put an end to that, changing the way he is perceived.
After that PSG victory, perhaps things must change.
We're hearing a lot this season that this is a new Chelsea, with a new manager. Even at his grand unveiling when Mourinho returned to west London last summer, he endeavored to make it clear he would be approaching things differently to his first stint in charge at Stamford Bridge.
While it's true some things have changed, Chelsea are feeling the benefit of those qualities that have remained no different in the decade since Mourinho arrived as the Special One.
The never-say-die attitude was there for all to see on Tuesday as Chelsea fought to the bitter end to outdo PSG. The breakthrough may have come in the 87th minute, but they got what they set out to achieve. Eventually.
The spirit Mourinho's team showed must be applauded, but it's born out of something that carries much more significance.
"We worked on a lot of scenarios," explained John Terry when he summed up the PSG game, per The Telegraph. "1-0, 2-0, 3-1, what we would do if Demba Ba comes on. Every scenario we had a game plan."
That attention to detail is what got Chelsea through on Tuesday night. And the hours spent on the training ground, working through those very scenarios Terry described is what gave the Chelsea players the spirit and belief they would eventually unlock a stubborn PSG rearguard.
It's nothing new, of course. Mourinho has long been famed for drilling his players relentlessly, driving home his tactics in minute detail.
What are tactics, anyhow? In an age of heat maps and tactical smartphone apps, formations and the evolution of player positions are what most hipsters deem important.
They play a part, sure, but it's the traditional sense of the notion that carries the weight—the action or strategy that is put in place to achieve the ultimate goal.
For Chelsea on Tuesday, the action came from the players, scoring twice to deny PSG. The strategy was very much Mourinho's.
When Option A failed, there were plenty more down the line to make sure of success. That's what breeds belief: It's what instills confidence in every player.
Mourinho's shown it before and he's proving again there isn't a finer manager at doing just that.
Chelsea fans have seen enough in the intervening years since Mourinho's first spell to testify as to the importance a manager has.
Where so many have got it wrong, Mourinho continues to get it right.
There are exceptions, of course—incidentally the folly in starting Andre Schurrle as his striker against PSG in the first leg of their Champions League quarter-final in Paris.
Mourinho dug himself a hole at Parc des Princes, and his players, on the back of a poor performance, helped make it a little deeper.
Whereas they would have struggled in years gone by, however, Mourinho's methods helped them overcome it. Action and strategy.
This is largely the same group of players that struggled into third place last season, suffering the ignominy of becoming the first team defending the Champions League to be knocked out in the group stage.
That tragedy and farce has long since disappeared into the rearview mirror. Chelsea are becoming a force again, which cannot go unnoticed. Nor can the genius that is helping them get there.
Garry Hayes is Bleacher Report's lead Chelsea correspondent and will be following the club from a London base throughout the 2013-14 season. Follow him on Twitter here @garryhayes