Manchester City fans have had few reasons to be concerned over the last seven years, but alarm bells will have been ringing after their 1-0 defeat at Aston Villa on Wednesday night.
Pep Guardiola's men were completely outplayed, managing just two shots in the entire match which came from the same passage of play, while Villa had 22 efforts on goal and could have won by more than just Leon Bailey's deflected strike.
City looked insipid in attack and vulnerable at the back, but the biggest issue was their lack of control in midfield.
Since Guardiola arrived in 2016, his side have relied on dominating the middle of the park, but they did not get a grip on the game at all at Villa Park.
John Stones, Manuel Akanji, Bernardo Silva and Rico Lewis all moved into central areas during the game, while Mateo Kovacic and Matheus Nunes came off the bench, but none of them had a meaningful impact.
Of course, City were missing their two best midfielders in Kevin De Bruyne and Rodri. But they have proved they can cope without De Bruyne over the years.
According to Stats Perform data, City have scored the same number of goals per game (2.5) since the start of the 2022-23 season when De Bruyne has played and when he has been unavailable.
Their win percentage also only dips slightly when he is not involved (73% to 65%), and their points per game is also only marginally less (2.3 to 2.1).
If you want to go back even further, De Bruyne also missed over five months of the 2018-19 season, but City still pipped Liverpool to the title.
It's a different story when Rodri isn't playing, though. Thankfully for City, the Spanish star has only missed five league games since the beginning of last season but it has made a huge difference to results.
The Premier League champions have only taken three points from those five games, losing four times.
Their average goals per game also drops significantly when Rodri is absent (2.6 to 1.4) and they concede 1.6 goals per match compared to just 0.9 when he is in the team.
It's evident that Rodri is the player that balances Guardiola's team, putting City on the front foot while also stepping in to break up counter-attacks.
He has played a vital role in City's unprecedented success, but the team have now become over-reliant on him.
City have spent big on the likes of Phillips, Nunes and Kovacic over the last 18 months, but none have developed into regular starters nor look ready to fill the void that Rodri leaves behind when he cannot play.
The summer transfer window was an important one for the club as they lost Ilkay Gundogan to Barcelona after he popped up with a number of crucial goals in the season run-in last term to help the side win the Treble.
Replacing him was always going to be a tough task, and City have not managed to do it.
Their title rivals Arsenal and Liverpool both had major midfield overhauls in the off-season, with Declan Rice and Kai Havertz coming in for the Gunners, while Klopp signed Alexis Mac Allister, Dominik Szoboszlai, Ryan Gravenberch and Wataru Endo to replace the likes of Jordan Henderson, Fabinho, James Milner and Naby Keita.
Neither of those teams appear weaker following those changes, but the same cannot be said for City.
Now, Guardiola has a midfield conundrum to solve to get his team back on track after four straight league games without a win.
The good news is that Rodri will return from suspension for today's trip to Luton, while De Bruyne was named in City's squad for the upcoming Club World Cup, signalling that he is closing in on a return to action.
But Rodri has missed four games through suspension already this season, and De Bruyne is now 32 with a history of fitness issues. Guardiola cannot count on both men to be on hand for every remaining game in 2023-24.
This leaves him with two options. He could give the likes of Phillips, Nunes and Kovacic more game time to build up their confidence, match intensity and a relationship with Rodri so they are better prepared to step in if he is not able to play.
The alternative is dipping into the transfer market next month. City have not tended to splash the cash too much in January over the years, but they could feel it is necessary after their dire showing at Villa Park.
Guardiola may have insisted earlier this week that his team are playing well enough to win the title but they looked a long way short of being the Premier League's best on Wednesday.
All is not lost for City. They have come from behind to win the league before - most notably last season - and it would be foolish to write them off just yet.
But they cannot afford more performances like Wednesday's showing at Villa, and Guardiola must fix his midfield problem to make City an unstoppable force once more.