MONACO -- Kylian Mbappe will take to the familiar Stade Louis II pitch Sunday with the unfamiliar feeling of doing it as a Paris Saint-Germain player for the first time.
If the France international's return to the principality was not already a big enough occasion, the encounter will see Ligue 1's top two go head-to-head in a must-win match for the hosts.
PSG come into this one with a six-point lead over Les Monegasques and know that a draw or a win and the consequent seven or nine-point gap from a positive result will almost certainly prove insurmountable for Leonardo Jardim's men.
With Mbappe, Edinson Cavani and Neymar -- or MCN, as they are now known -- on fire, even a first defeat of the season for Unai Emery's side might not be enough for ASM to stop their rivals from immediately stealing back the Championnat crown after they were dispossessed last season.
Essentially, this could be the moment when Les Parisiens kill off their closest competitors as they get ready to enter the business end of term after the rapidly approaching winter break.
Mbappe, 18, will be key for Les Parisiens on Sunday night, but whether he starts or is a substitute, as he was for the recent 4-1 home win over Nantes, all eyes will be on him in Monaco as he comes up against his formative club.
"It is a great thing for Kylian to return to Monaco," Emery said at his prematch news conference Friday. "He is very happy with what he achieved there.
"It will be a special match for him, but he will give 100 percent for PSG."
It has been a good start to life in Paris for Mbappe overall, with four goals and four assists in Ligue 1 alone.
He was part of a front three that ruined Celtic 7-1 in the UEFA Champions League in midweek, but Emery believes that the best is yet to come from French football's golden boy.
It certainly seems that way with Cavani and Neymar -- despite their far from smooth start to their time together -- looking more settled as part of an all-star front three than the prodigiously talented wunderkind from Bondy thus far.
"Kylian wants to grow further and develop here," the Spaniard told journalists at Camp des Loges. "He still needs to learn how to adapt to defences that play deeper against us though."
"The system he played in at Monaco was different from ours."
Mbappe exploded onto the European football scene with Monaco in incendiary fashion last campaign with 15 goals and eight assists from 29 league appearances alone.
He even featured for Monaco when the teams last met in the French season-opening Trophee des Champions in Morocco in July.
However, this will be his first outing as an opponent at Stade Louis II, and Jardim -- the man responsible for his senior breakthrough -- believes that he has already shown some glimpses of the player who illuminated that unique venue in Ligue 1 and the Champions League last term.
"Kylian has produced some beautiful performances with PSG so far, at the same level as last season," the Portuguese said at his prematch news conference. "His potential to develop is huge -- he is still just a kid."
Jardim added that the pair enjoy "a father-son relationship" before turning his attention to the question of how to handle such a talented player.
The man from Barcelona, Venezuela, underlined his credentials as one of Europe's most underrated tacticians when he masterminded a 3-1 home win for Les Monegasques over PSG last season, and that result contributed to his massive rise in status by the end of an incredible campaign.
That time, Jardim pinpointed former ASM player Layvin Kurzawa -- a player he previously coached -- and used his knowledge of the France international to exploit the men from the capital on their left.
The former Sporting CP boss was less optimistic about tripping their rivals up this time around because it is not only Mbappe (and possibly Kurzawa) whom he will have to think about.
"How to counter Kylian?" Jardim mused at Monaco's picturesque La Turbie training complex when asked by the press. "It is not just him -- PSG have many players and all of them possess great quality.
"We will need to be compact and not give them a lot of space but also try to attack them."
In order for that to happen, Monaco will need possession of the ball, something that PSG do not give up lightly to their opponents.
Therefore, the battle between the two midfields might be more decisive than how Jardim gets his players to handle former teammate Mbappe or how he can exploit Kurzawa again -- especially considering the left back's average overall form so far this term.
Monaco's players cannot allow themselves to focus on Mbappe like most spectators will be doing Sunday, because if that is what they end up doing, PSG's No. 29 is likely to run rings around them and lead his new employers to a potentially decisive Ligue 1 win.
Instead, the home side might be better off hoping that a sold-out Stade Louis II crowd turn a bit hostile to unnerve him and that the emotion attached to such a homecoming gets the better of the young Mbappe and gives them one less thing to worry about.
With the teenage sensation out of the equation, they would then only have to worry about the in-form Cavani, Neymar and the rest of the visitors' star-studded roster.