Vastly differing perceptions of success separate Sunday afternoon's adversaries at the Parc des Princes.
Rennes arrive at the stadium on the leafy western fringes of the French capital harbouring ambitions of finishing fourth or fifth and obtaining a place in the Europa League or the Europa Conference League.
Their hosts, Paris Saint-Germain, will be vying to open up a 13-point lead on second-placed Marseille who play on Sunday night at Reims.
With 11 games remaining only a catastrophic sequence of results can deprive PSG of a ninth Ligue 1 title in 11 years and a record 11th top flight crown.
It would also be their 30th piece of silverware since Qatari Sports Investments (QSI) took over full control of the club just over a decade ago.
And yet with glory simmering on the horizon, sections of the PSG faithful may well disgorge their bile on the players and coaching staff for failing them – yet again – in the Champions League.
Cash
Despite the best part of two billion euros spent on transfer fees alone in the QSI era, PSG have only reached one Champions League final – the 2020 loss to Bayern Munich.
And they followed that setback with a semi-final defeat to Manchester City in 2021 when Mauricio Pochettino was in charge.
In 2022, Pochettino's side – which included Kylian Mappé, Lionel Messi and Neymar – imploded from 2-0 up in the last-16 to lose 3-2 on aggregate to a Karim Benzema-inspired Real Madrid.
Within the past few weeks, PSG under Christophe Galtier, have gone down 3-0 on aggregate to Bayern Munich in the last-16.
In the first home game just after the Madrid debacle in 2022, fans booed Messi throughout the 3-0 waltz past Bordeaux which sent PSG 15 points clear at the top of Ligue 1.
Jeers?
A year on and the 35-year-old Argentine might well be in for similar invective against Rennes.
Neymar, injured, and out for the rest of the season, ought to be spared. Open criticism of Mbappé? Highly unlikely.
The 24-year-old France international – who added a record- extending 202nd goal for PSG in the 2-1 win at Brest last Saturday – has effectively become their talisman in a seemingly Arthurian quest for the Champions League.
"In terms of ability, in terms of charisma, he is one of the great stars of the game," said Jonathan Wilson, editor of the British-based football magazine The Blizzard.
Change
"In Messi and Neymar, you've got expensive, ageing players. But quite apart from an issue of rejuvenation, there is a problem with the culture of PSG," Wilson added.
"It's so celebrity driven that I think it adds to this sense of indulgence and this softness.
"The fact that PSG is so much stronger than everyone else in Ligue 1 means they're not really tested. And so every time they come up against a decent team in the Champions League, they really struggle.
"Watching the Bayern Munich games this season, PSG weren't even close to Bayern and I don't think this is a very good Bayern Munich side."
Galtier – who led Lille to the 2021 Ligue 1 title before going to Nice – was drafted in last summer to add backbone and a collective ethos to the parade of stars.
Challenge
His methods appear to have been effective domestically. But in Europe? So far, not so good.
"The players know that we still have to win games," said Galtier on the eve of the clash against Rennes.
"The only motivation is to be French champions for the 11th time.
"Rennes are always a formidable team and we must be careful. We are going to face teams in the next few weeks who are playing for European places. If we take the title for granted, we could get a nasty surprise."
But 'twas ever thus for PSG bosses. Defiance amid the maelstrom in the abyss.
"I think PSG have followed that path of putting the cart before the horse," added Wilson
"The first thing owners need to do is work out how do we want the team to play ... and then appoint a coach to make that happen.
"And then you get in the players who can enact the coach's interpretation of your vision rather than going out and signing the stars and then putting a coach in and saying: 'Well, see what you can do with that.'"
Carlo Ancelotti, Laurent Blanc, Unai Emery, Thomas Tuchel and Pochettino have led the side over the past decade to domestic dominance.
But the most prestigious trophy in European club football remains infuriatingly – for the PSG fans – out of reach.
Balance
Just after Neymar's ankle injury ruled him out for the rest of this season, Galtier admitted his absence would bring better balance to the team if Messi and Mbappé were playing.
Galtier did remark though that Neymar's presence was always more likely to bring goals.
"PSG have had different types of coach playing different types of football with different management approaches," added Wilson.
"None of them have worked because essentially the club is unmanageable."
Rampaging around foreign fields on a Champions League night has happened only once in Rennes' 122 year history. That campaign in 2020/21 ended at the group stages.
Rennes have returned to Europe with moderate success. The last-16 in the Europa Conference League in 2022 and defeat in 2023 to Shakhtar Donetsk in the play-offs for the last-16 in the Europa League.
They lie four points off Monaco in the fight for fourth place and a return to that tournament.
Lille, Nice, Reims, Lorient are chasing them for the berth leading to the Europa Conference League.
Their passage to Uefa's third tier competition was hampered when they drew 0-0 at relegation-threatened Auxerre on 11 March.
"If we play against PSG like we did against Auxerre, we'll be thrashed," said Rennes boss Bruno Genesio.
"I do expect a reaction from the team because we're going to be taking on the reigning champions who look like they're going to win the title again. They are a formidable opponent."
Only domestically, Bruno. Only domestically. PSG's Champions League conquerers Bayern Munich were drawn on Friday against Manchester City in the quarter-finals.
Defending champions Real Madrid will take on Chelsea while Napoli – in the last eight for the first time – will play Serie A rivals AC Milan. Inter Milan will face Benfica.
Talent
"One of the most striking failures that PSG have had is failing to exploit the local market that they've got access to," added Wilson.
"The suburbs around Paris – along with south London – are one of the great hotbeds of football talent.
"And yet how many Parisians are there in the PSG squad? Two 17-year-olds and Mbappé – who they bought for 160 million euros from Monaco.
"And I'm not so sure PSG can build around him. I'm not sure he is a particularly good example of a leader.
"He let that interest of Real Madrid develop and he used it to get himself more money. I'm not sure I'll be pinning my hopes on him. Is he going to stay another two years? Three years?
"I wouldn't be convinced of that at all. I think it's far more about getting a collective spirit which is something PSG have never had under the QSI ownership and making it less about celebrities and more about how do we actually get this team playing high level football and winning matches in the competition that matters."
A poser indeed for the supremos of Paris Saint-Germain.
Perhaps they should all head to a cafe on Boulevard Saint-Germain for some existential thinking.
