Paris Saint-Germain will be playing for their Champions League lives against Manchester United on Wednesday, with last season’s runners-up knowing the costs of group-stage elimination could be enormous on and off the field.

Anything less than victory at Old Trafford and the French champions could see their destiny slip out of their hands going into the last game in Group H.

Neymar’s penalty gave the Qatar-owned club victory over RB Leipzig last week, but Thomas Tuchel’s team performed poorly and the coach’s agitation when searching questions are put to him by the press suggest all is not well in Paris.

PSG are top of Ligue 1, although their lead has been trimmed back in recent weeks following more disappointing displays.

"There is no way we can play like that in Manchester, like we did in the second half,” Tuchel warned after Saturday’s 2-2 draw with Bordeaux.

There will be potentially major consequences if they fail to qualify for the last 16 of the Champions League, something they have managed in each of the last eight seasons since becoming regulars in the competition again after the Qatari takeover.

Tuchel is out of contract after this season and sporting director Leonardo is not believed to be a huge fan of the German, even if he recently dismissed reports he was looking for a replacement.

"Honestly the club has never thought about another coach to replace Tuchel. Now is the time to concentrate on our objectives and to stick together,” Leonardo said in a question and answer session with supporters.

Despite that, it is hard to imagine Tuchel surviving in the event of a European disaster, as being dumped out at the first hurdle would be a huge blow to PSG’s prestige.

Over the last decade it has become almost impossible for such ignominy to befall one of Europe’s super clubs, a category into which PSG now fit as the fifth-richest in the world according to Deloitte’s Football Money League.

Barcelona have made it out of their group in every season since returning to the competition in 2004, while Real Madrid have got out of their group in every year since 1997.

Bayern Munich have done so in every year since 2008. Manchester City have already secured an eighth consecutive appearance in the last 16, Juventus a seventh.

After revelling in the team’s run to the final in Lisbon, PSG’s Qatari owners would not take kindly to such a sporting slap in the face.

Financially, the repercussions could be serious.

PSG are looking at ways of extending the contracts of Neymar and Kylian Mbappe, whose existing deals expire in 2022, but how can they in their current financial predicament?

Documents released in 2018 by Football Leaks showed Neymar’s after-tax salary to be 30 million euros ($35.8m) a year while Mbappe’s salary was due to rise to 11 million euros this year.

If PSG are prepared to offer whatever it takes to keep them, will they be able to invest in the other areas of the team that need upgrading?

They have been hamstrung by the coronavirus crisis, suffering huge losses from the decision to cut short the last French season.

RMC Sport recently reported that PSG were preparing for a loss of some 200 million euros this season, chiefly from lost gate receipts due to the pandemic.

A group-stage exit from the Champions League would only make things worse.

Just reaching the last 16 was worth 9.5 million euros last season, while reaching and winning the final was worth another 41.5 million euros, enough to cover the wages of Neymar and Mbappe for a year.

UEFA is set to reduce prize money over the next few years because of the impact of the health crisis, but PSG can ill afford to miss out on these sums. The stakes in Manchester will be high.