After eight years, seven trophies, two Champions League finals and one shiny new stadium, the time has come for change at Atletico Madrid.
Saturday's 1-0 derby defeat to Real Madrid was only its fourth loss in La Liga this season, but it leaves it 13 points behind the leader and with no sign of that gap closing between now and May.
Madrid needed 56 minutes to break the deadlock through Karim Benzema, which is nothing new for Atleti – it remains redoubtable in defence, with only Los Blancos conceding fewer league goals this season – but its listlessness in attack is reaching crisis point.
Atleti has scored 22 goals in La Liga, as many as fourth-bottom Real Mallorca. It has failed to score in four of its past five matches in all competitions, the exception being Angel Correa's goal in a truly disheartening Copa del Rey defeat to Cultural Leonesa. Most worrying of all is the fact it has won six times since October 29.
The typical ferocity with which it has played under Simeone since December 2011 is now seemingly exclusive to the head coach himself, who was booked in the first half at the Santiago Bernabeu after one too many furious marches from his technical area.
In short, Atleti is bereft of confidence, insipid going forward and with little obvious idea how to arrest its poor form. It is fifth in LaLiga, out of the Copa, beaten on penalties in the Supercopa de Espana final by its city rival and with the daunting task of Liverpool to come in the Champions League. It is falling alarmingly short of expectations, especially given a pre-season investment of nearly €244million.
Simeone has not been helped by injuries. Joao Felix, the €126m man who devastated Madrid in the 7-3 International Champions Cup win in August, sat out Saturday's defeat due to a muscle injury, although his recent form means he would have been fortunate to start anyway. Diego Costa, who scored four against Madrid in that resounding pre-season success, has not started a league match in three months. Alvaro Morata, its one fit centre-forward, went off at half-time with an apparent muscular problem.
But excuses are running out for Simeone. The man who has worked miracles at times in turning Atleti from second-class citizens in Spain's capital to persistent La Liga and Champions League contender looks like his magic has worn off. The feel around the Wanda Metropolitano, the sparkling Atletico venue designed to reflect its modern prowess on the pitch, is much the same as the atmosphere at the Tottenham Hotspur Stadium in Mauricio Pochettino's final months in charge: how will anything change unless there's a new man in the dugout?
Atleti did at least start positively against Madrid and created the better chances in the first half. Angel Correa clipped the outside of the post and Vitolo brought a smart save from Thibaut Courtois from inside the box. That, though, was its only shot on target.
At half-time, Zinedine Zidane abandoned his plan to midfielder Atletico to death, bringing on Lucas Vazquez and Vinicius Junior. One timely pass from the Brazilian allowed Ferland Mendy to set up Benzema for the winner 56 minutes in.
Atleti's best attempt at a comeback was a solitary wayward shot from Thomas Partey with 20 minutes left – irrefutable evidence of the team's stagnation under Simeone. "Stay, Cholo!" came the ironic taunt from the home fans. How much longer will the Atleti faithful sing the same thing and mean it?
His legacy at the club is secure, but his future, and that of Atleti, is weakened with every passing miserable 90 minutes. A parting of the ways, now or before next season at least, might be best for all concerned.