Kylian Mbappe announced on Monday that he will take on Usain Bolt over 100m. Should Paris Saint-Germain fail to make it past Borussia Dortmund, they might as well race on the runway at Charles de Gaulle.

The absence of a Champions League final will quicken Mbappe’s exit for Real Madrid. To the rest of the world, it will also mark the end of his time at PSG. There is still a French Cup final against Lyon this month, but this is the match and the competition that matters.

After seven years, it is not unreasonable to say that two games — Tuesday evening's match at Parc des Princes and the final at Wembley on June 1 — will determine his legacy in Paris. That is not to say he will be unfavourably remembered if he doesn’t win the Champions League. The majority love him here, in the capital and beyond. Despite being Paris-born, it is his relationship with the club’s ultras that is more complicated.

But to most Mbappe is the Galactico who cared, who always sought to maximise what he gave on the pitch, even if that meant becoming embroiled in power struggles off it. The power, in truth, has always resided with him.

If there is a major event here in France, the country wants to know what two people think. Firstly, president Emmanuel Macron. Then, Mbappe. Macron, however, probably wants to know what Mbappe thinks first.

PSG's clash with Dortmund and a possible final could define Kylian Mbappe's time in Paris

The petit president has always aligned himself with this sporting giant. He celebrated with him after victory in the 2018 World Cup final, and made straight for Mbappe — and votes — when consoling him on the field following defeat four years later.

A recent invite from Macron to attend a state dinner with the Emir of Qatar at the Elysee Palace underlined Mbappe’s allure and status. He is smart enough to accept the invitation, too. He turns up, plays the game and leaves with his face on the front page of every newspaper. But none of that matters tonight. Here, he must turn up, play the game and leave with his smiling face decorating the back pages.

PSG’s success or otherwise, you feel, will depend on the 25-year-old, much like it did in Dortmund last week. Because for all that Luis Enrique has forged a team that is suddenly well structured, hard-working and likeable, the piece de resistance remains Mbappe. He started centrally at Signal Iduna Park but was, for too much of the 1-0 defeat, existing on the periphery. A merit score of 3.9 out of 10 from readers of L’Equipe captured how ineffective he was.

His ego would have been bruised on a night when he was upstaged by Jadon Sancho. But that usually means someone is due a beating, and Dortmund could be left black and yellow in more ways than one if Mbappe comes out fighting. They know it, too.

‘We’ll need to starve him of service,’ said Dortmund captain Mats Hummels, who pocketed Mbappe (below) in the first leg. ‘If he gets a chance, he will score.’

PSG’s ultras are planning a tifo display before the game but they are unlikely to celebrate Mbappe, who has never been a favourite of the hardcore.

‘The connection between the player and the ultras has taken a winding trajectory, its seven-year term punctuated by echoes of departure or (contract) extension almost every summer,’ L’Equipe noted yesterday. ‘As if there has always been a restraint in venerating a player who it was clear from the moment he arrived was just passing through.’

Mbappe’s passage is almost done. The sceptics would say he has long since had the finishing line in sight.

But if he and PSG can cross it together as European champions, the ultras might just make a tifo of him yet.