For Ole Gunnar Solskjaer, this moment is the challenge he has been preparing for. For Maurizio Sarri, this spell is challenging all his preparations.
And, for the third season in a row, an FA Cup meeting between Manchester United and Chelsea is about so much more than one of football’s most historic trophies. It is about the immediate futures of both managers, and the medium-term futures of the clubs.
Just winning this match is arguably more important to both men than winning the trophy.
Another defeat for Chelsea would just prolong this problem period, emphasise there are still few signs of Sarri’s plan coming to any kind of fruit, and bring him closer to the sack. It might well put him on the brink.
Solskjaer has enjoyed a spell of form that has felt like the complete opposite of Chelsea’s over the past two months, which is why United have overtaken them in the league to go into the top four, but that is why this immediate aftermath of that first defeat - to Paris Saint-Germain - feels so freighted.
While a loss to a team as good as the French champions obviously isn’t any way damning in itself, the crux issue now is that it will test how much of United’s form has just been down to switch of mindset offered by Solskjaer; how much was propelled by the good feeling from the mere change of manager of itself after such a spell of depression at the club; how “illusory” the last two months have been.
They have sometimes felt a dream, given how sensationally well the period has gone. It couldn’t really have been better.
So if PSG represented a reality check, a second successive defeat would be a proper grounding. It might be where the real work starts, and where Solskjaer’s pitch for the job really begins.
Although the United hierarchy have so far been greatly impressed by the Norwegian, and already had discussions about keeping the job after this season, those are the kind of impressions that can evaporate into nothing with one bad month. It wouldn’t take too much for the club to reconsider everything, especially when nothing is signed. Two defeats, and going out of the competitions they can still win so quickly, would greatly change the mood.
Chelsea meanwhile want to persevere with Sarri and this wider change of direction, but feel continued bad results - and especially elimination from the Europa League - might just be too much. It might well necessitate another change.
And for both managers, of course, this isn’t just about winning this game. It's about the potential effect of this game on other results.
For both, it isn’t quite about the specifics of football, but something deeper. It is about preventing a rot.
Solskjaer will know Sir Alex Ferguson dwelt on this challenge more than any other manager, given how long the great Scot was in the game and how many slumps he actually had, as well as how the Norwegian was there front and centre for one of the biggest.
Solskjaer was United’s main striker in the autumn of 1996, as they lost three successive games in the league: 5-0 to Newcastle United, 6-3 to Southampton and 2-1 to Chelsea.
Ferguson’s response was psychological as much as anything. He “drummed it into the players it was imperative” they “put it right” and how losing can easily “become a habit”.
“My main objective all week has been to remind the players what the club requires of them: in particular hunger, determination and pride,” he revealed in his superb book on the 1996-97 season, ‘Will to Win’. “Build on those foundations and you build to last.”
“I have to grasp the nettle and be honest about the areas where we are failing. This is no time to fudge issues or make issues.”
For his part, Solskjaer repeatedly said through that winning run that the big test would be how they react to a setback. He has been conscious of maintaining the mood of confidence and adventure, even if that is now complicated by key injuries to Anthony Martial and Jesse Lingard. He’s going to have to adapt to that, too, but he knows not to panic. He has been doing what Ferguson maintained you must in such situations, and reminding the players of the standard.
It’s more difficult for Sarri. He has tried to be honest about where Chelsea are failing, but it is all such a “fudge” - to use Ferguson’s word - despite that.
That’s certainly how his football feels in the minds of his players. Many have recently been complaining of an “overload” of tactical instructions, that has just resulted in confused and ponderous football.
Those more sympathetic to Sarri say the squad isn’t “tactically intelligent enough” to comprehend his demands. Whatever the truth, it does point to what feels a lack of fit between the players available and manager, that in itself points to the lack of unifying football vision at Chelsea.
It also puts Sarri in something of a quandary. The Italian has to stay true to the principles of his own long-term vision, but that is at risk by the problem of short-term results.
His assistant Gianfranco Zola articulated this ahead of the United game.
“What we're trying to do is ambitious in a competitive league, and it's not easy. But we believe it's the right way and we carry on. There's no point in making things too difficult for the players. We just need to stick to what we're doing and try to make it better. Focus on that.”
All focus is now on the FA Cup fifth round, but because of its greater consequences.
For all the questions about Sarri's motivation - not least from himself - Chelsea have admittedly displayed the responses required for such games already this season. They followed that defeat at Wolves - which was a second in three games after their first under Sarri, against Tottenham Hotspur - with that defiant 2-0 win over Manchester City. They responded to the manager’s diatribe after Arsenal by eliminating Tottenham from the League Cup, setting up a final with City that only makes this week all the more momentous.
It also makes their preparation, and thereby this game, all the more consequential.
It’s just they’re facing a team who have similarly had the stakes raised.
This match is about more than FA Cup. It’s about proving there’s much more to these managerial regimes.
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