Paris Saint-Germain will play perhaps the most pivotal match in the club’s history when they host Borussia Dortmund in the Champions League on Wednesday.
Failure to overturn their 2-1 deficit from the first leg would surely signal the end of the most ambitious era of the club; the one in which they made Neymar and Kylian Mbappe the two most expensive players in the world.
A combined €400 million (£347m/$454m) was spent on attracting the offensive duo, so a third successive last-16 exit would represent a miserable return on their record-breaking investment and very probably prompt a change in direction, as well as coaching staff.
Merely winning Ligue 1 at a canter on an annual basis is not going to satisfy the ambitions of Mbappe, who has known nothing but success during his short career.
Neymar, meanwhile, still strives to be recognised as the finest player in the world but has little hope of winning the Ballon d'Or – which has an almost mythical status in Brazil – unless he plays a starring role in a Champions League triumph.
In that context, it was hardly surprising that he made his dissatisfaction with his present employers clear after the lacklustre loss in Dortmund three weeks ago.
Just like PSG in general, the Brazilian was out of sorts at Signal Iduna Park, despite scoring the goal that gives the French champions hope of reaching the quarters, and was quick to point the finger at the club for his lack of match sharpness.
“It’s hard not to play for four games,” he grumbled after being omitted from the starting line-up in the preceding weeks because of a rib problem. “Unfortunately, it was not my choice, it came from the club, the doctors; they’re the ones who made the decision, one that I did not like.
"We’ve had a lot of discussions on that. I wanted to play, I was feeling well but the club were afraid, and in the end I’m the one suffering.
“Had I been in better shape, I would certainly have played better.”
Having previously flirted with both Real Madrid and former club Barcelona, Neymar is clearly not the kind of character that would be willing to hang about if PSG continue to self-destruct in Europe.
Mbappe, meanwhile, has made clear his admiration for Madrid, where boyhood heroes Zinedine Zidane and Cristiano Ronaldo played successful portions of their careers.
“Everyone talks about it (a transfer to the Bernabeu) – when I was young, I talked about it too,” Mbappe admitted to the BBC in January. “But now I'm a PSG player and I know it's not the moment.”
That moment, however, may come at the end of the season, when the 21-year-old approaches a critical juncture in his career due to a contract that expires in 2022.
If PSG cannot extend his deal, they will be faced with a big decision in the summer.
Retaining the World Cup winner until 2021 would be fraught with risk, given they would then be compelled either to find a new contractual agreement, sell him for what might be a comparatively low fee or risk losing him for nothing at all a year later.
So, ahead of the visit of Dortmund, the stakes could not be higher for PSG and, worryingly, the signs for Tuchel and his squad are not positive, even looking beyond their remarkable ability to find innovative ways to crash out of the Champions League last 16 on an annual basis.
The decision by the local authority to force the game to be played behind closed doors due to the threat of spreading coronavirus may be logical from a public health standpoint, but for the Parisians it takes away much of the benefit of playing at home on an evening upon which they need everything to go right for them.
Additionally, Mbappe missed training on Monday and Tuesday suffering from a sore throat and although his coronavirus test thankfully came back negative, his illness suggests that he will not be at full capacity come kick-off.
After a relatively difficult period in his career, he has returned to form since the first leg, starring in a 4-0 victory over Dijon and then netting a hat-trick in a 5-1 Coupe de France defeat of Lyon.
Such performances allowed sporting director Leonardo – who criticised the “negativity” surrounding his side prior to the first leg – to purr over the quality of his forwards: “Tell me who the best five players in the world are? We have Neymar and Mbappe. Who should we be scared of?”
That message clearly did not get through to the squad in Germany, though, with Tuchel criticising them for a performance that had “too much fear”.
If they produce a similarly inhibited display on Wednesday evening, the next time the Champions League music rings out around Parc des Princes, the fans will be present – but Neymar and Mbappe might not.