José Mourinho has torn up his original blueprint, and the overhaul has given Real Madrid a completely different look.
Six wins on the bounce have followed. Among Europe's elite, only Paris Saint-Germain and their run of nine straight victories can better that.
In a report, Marca newspaper noted that Mourinho is still treading carefully and refusing to let optimism run away with him, saying: "When you win, everything looks better than it really is."
The changes to his line-up are plain to see. "I am not a stubborn coach," he told a press conference, trying to explain the shift in approach he set in motion after Roma scored their third goal at the Olympic Stadium.
Chief among his big calls has been pushing Fede Valverde into the right-back role, ahead of the specialists in the squad, Dumfries and Trent Alexander-Arnold.
"I do not like it, in fact it pains me, but I put the interest of the team first," said the Portuguese.
That decision is tactical at heart, yet it says just as much about the coach's standing in the dressing room and his grip on the players.
Last season Valverde rebelled, snapping "I was not born to play in the full-back position" after Xabi Alonso asked him to cover for the absent Carvajal and Arnold. Now the Uruguayan is a model of obedience: "I am ready to play in any position the coach asks of me."
One of the biggest reasons behind Real's upturn is simple. Mourinho has scrapped the rock-solid holding pairing of Valverde and Tchouaméni.
He has also hit upon the formula that lets Arda Güler and Bernardo Silva feed the forwards and manufacture chances.
Diomande surpasses Vinícius
This collective improvement brings another key element, and at the same time it poses an awkward question. Diomande's arrival in the side gives Real Madrid a more collective feel. His ability to make the difference is no less than that of Vinícius Júnior, and in front of goal he has gone one better: four goals for the Ivorian against a single strike for the Brazilian.
What is more, the real Marc Cucurella has emerged with Yan Diomande ahead of him.
Vinícius returns to action in Athens. But every appearance now comes loaded with sky-high demands and expectations. He has to win back his place, prove he belongs in the starting XI, and show that his individual brilliance does not come at the cost of a team whose engine has fired into life and refuses to stop winning.
It is a new situation for the man in the number 7 shirt. His coach keeps sending messages of support, but the plain truth right now is that Diomande has the first word on the left flank.
Vinícius Júnior must respond, and quickly, to change a reality in which the cards of power are no longer in his hand as they once were.
Alongside all this, Mourinho has brought Eduardo Camavinga and Endrick back into the fold, after both had looked to have slipped out of his thinking. Expect sweeping changes against AEK Athens.
"There is a mutual understanding between the coach and the players. We have come to understand each other in matters we did not understand at the start," Mourinho said.
And as Cadena SER reported, the Real Madrid players hoisted their coach onto their shoulders in the dressing room at the Camp Nou. The results speak for themselves.