Everything about life at Paris Saint-Germain currently appears to be experienced on a knife-edge.
From the club’s fragile position in the Ligue 1 title race, one point behind leaders Lille with three games to play, to the 2-1 deficit they are aiming to turn around in their Champions League semi-final against Manchester City, on the field things are too close for comfort.
Off it, the contract situations of both Neymar and Kylian Mbappe are only creating further question marks heading into the final month of the season.
The largest of those hangs over Mbappe, whose future remains in the balance amid interest from Real Madrid, and whose physical condition has been questioned ahead of the trip to Manchester on Tuesday.
Images of the forward walking into the airport on Monday apparently with a slight limp have done little to allay such fears, either.
"Today he is going to start an individual training session and see if he can be with the team," Mauricio Pochettino said upon his team's arrival in England.
“Yes, I am worried for him. There is still one day and we will see and decide if he is going to be available."
World Cup winner Mbappe has tended to save himself for these big European away nights. A hat-trick against Barcelona then a double against defending champions Bayern Munich in successive knockout trips have him to the forefront of the Ballon d’Or race.
City, though, successfully shut Mbappe down on his home turf of Parc des Princes last week.
His influence was limited to a thrilling breakaway early in the second half that saw him zip a cross along the six-yard box that Marco Verratti was inches away from touching to make it 2-0.
Otherwise, the 22-year-old failed to muster even a single shot, despite ostensibly being PSG’s No.9 for the evening.
If the nature of the second-half collapse led to Pochettino’s management of the side coming under scrutiny, so too did Mbappe’s uncharacteristic lack of end product.
This was only magnified on Saturday, when it became evident that Mbappe would miss a potential banana skin match against Lens because of a calf injury.
The origin of this problem, though, was not the fixture against City, but in the closing stages of a Ligue 1 encounter against Metz the previous weekend.
“I think we handled him perfectly,” Pochettino objected when probed about Mbappe playing the full 90 minutes in Metz.
“We said that against Metz, he hardly touched the ground when he was running. He was almost flying because he was so good physically.
“In the match before that, against Angers in the Coupe de France, he was rested. And he played the game before that.
“He suffered his injury at the end of the match against Metz. It could have happened in the first minute. It could happen any time you’re on the pitch.”
Nevertheless, the sheer weight of minutes that Mbappe has been expected to play this season, despite suffering from Covid-19 at the start of the campaign has been formidable.
When his minutes are combined, Mbappe has played more than 37.5 total games spread across 43 appearances since September 20, despite complaining of fatigue in the autumn.
“For me, the feeling is that I'm in the 60th game of the season and not in the ninth,” he told the club’s official website. “We've had a marathon of games.
"Generally, when you get to a Champions League final, you have a holiday, but we got to the final and we didn't have time to rest.”
His statistics may not have suffered – he has scored 37 goals and laid on a further 10 assists – but his performances have not been the consistently explosive variety that fans the world over have grown used to seeing from this shining light of the game.
Mbappe, though, has successfully roused himself for the big occasion this season, as Barca and Bayern have already found to their cost.
And fixtures scarcely get any bigger than Tuesday’s match at the Etihad Stadium.
PSG will have to chase the game and find a way to impose themselves upon the Premier League champions-elect for the full 90 minutes, much like they did during the first half in the French capital.
It will require an impeccable performance from back to front, and though it is not an impossible task given the tools at PSG’s disposal, it is one that they surely need Mbappe to be at his best for.