For much of the season, Chelsea were being measured against two of the greatest teams in Premier League history.
Manchester City and Liverpool have set a new standard of excellence in English football, racking up record points totals to secure titles in recent seasons.
However, after surprisingly winning the Champions League last May, Thomas Tuchel's Chelsea appeared perfectly poised to break up the duopoly, as underlined by their ascent to the top of the Premier League table in December.
Since then, though, a mixture of Covid-19 outbreaks, injury problems and fixture congestion has slowed their progress.
Chelsea have continued to show themselves to be a force to be reckoned with in cup competitions but, unfortunately, the atmosphere around Stamford Bridge has changed, and not just because of the club's ongoing ownership issues.
Indeed, Tuchel is more concerned with what he is seeing on the field right now, having been left enraged by his side's concession of 11 goals in their last three home matches.
"It's impossible to have this amount of mistakes at this kind of level," the German fumed after another shambolic defensive display in Wednesday night's 4-2 loss to Arsenal.
"You just don't see this ever, yet we're doing it at the moment. You cannot win football games like this. It's simply impossible."
Worryingly, there's now just a five-point gap between third-placed Chelsea and both Tottenham and Arsenal, who are fourth and fifth, respectively, and separated only by goal difference.
The Blues have a game in hand but it's a damning indictment of their slump in form since the turn of the year that they are now looking over their shoulders rather than forward to a title fight with City and Liverpool.
Indeed, the concern is that they could actually be drawn into a top-four battle with mediocre sides like Arsenal, Tottenham, Manchester United and West Ham, who have all proven maddeningly inconsistent this season.
So, what's gone wrong at Chelsea?
Upon arriving in west London in January 2021, Tuchel's main message to the dressing room was that he wanted to make his side "horrible to play against" having seen Frank Lampard's tenure marred by dreadful defending.
When asked at the end of last season to explain the key to his side's sudden improvement on his watch, "At times, we just hang in and fight.
"We use our bodies, we use our work rate and if we can't out-play [the opponents], we are ready to out-work them with hunger and energy."
It was an acknowledgement that Chelsea didn't have superstar match-winners like Mohamed Salah or Kevin de Bruyne; that they needed to find other ways to win games.
It was easier said than done, of course, but the players really bought into it, with Tuchel creating a culture of hard work which translated into high-intensity football and incredible levels of concentration.
The upturn in form also coincided with a switch to a back three which added an extra defensive player at the back, making the Blues hard to break down.
While the objective remained to hoard possession when possible, the focus changed to pressing well and counterattacking rapidly.
The emphasis on defending stunted the club's ability to produce fluid attacking displays but clean sheets were prioritised, not least because attackers such as Kai Havertz and Timo Werner were not proving a reliable source of goals anyway.
"We are not the team that can escape with results if our input is at 90 per cent or 80% of our energy, commitment and investment," Tuchel said after his side's 6-0 win away at Southampton.
"We must have our priorities right. If we are committed, if we defend with courage, if we have the attitude right and the hunger right, and win challenges, we are a special group."
Of course, the hope was that the acquisition of a proven goalscorer last summer would add an extra dimension to Chelsea's attack.
However, Romelu Lukaku's club-record £100 million ($136m) transfer from Inter could not have gone much worse.
The Belgian hasn't adapted well at all to Tuchel's tactics, as he himself effectively admitted in the already infamous interview with Sky Sport Italia, which, while perhaps blown out of proportion, was badly misjudged in terms of tone and content.
The fallout only further alienated Lukaku and that major issue, coupled with the expiring contracts of key defensive duo Antonio Rudiger and Andreas Christensen, has had an unsettling effect on the dressing room.
With everyone united last season, Tuchel could rotate at will. Now, it is a more delicate balancing act trying to keep every member of the squad motivated and energised, particularly when one considers that Chelsea have played more games than any other side in Europe this season.
Even Tuchel himself isn't as happy as before. He has handled the ownership crisis with grace and class, but it was revealing to see him using the Stamford Bridge pitch as an excuse for his side's dip in form.
Chelsea have certainly had to deal with more stress and strain than most this season, but the onus really is on them now to finish a turbulent campaign with a flourish to ensure that they can start looking to emulate the elite sides above them in the table next season rather than becoming just as mediocre as the teams below them.
