Jose Mourinho says he believes that Kylian Mbappe is far and away the most valuable player in the world, adding that the young French forward is currently "unbuyable".
Mbappe joined Paris Saint-Germain from Monaco in 2017 with the club paying €180 million (£166m/$212m) to acquire his services.
The move made him the most expensive teenager ever as well as the second most expensive transfer ever, only behind PSG team-mate Neymar.
Mbappe has since helped guide France to the World Cup crown in Russia in 2018, while scoring 26 goals in 23 Ligue 1 appearances this season.
And Mourinho, who recently said he values Mbappe higher than Cristiano Ronaldo or Lionel Messi on the world market, says the forward is all but unbuyable for every club in the world.
"I don't tell he is now the best player of the world. But in my opinion, he's the one with the most important market value today," Mourinho told Canal Plus.
"If I was manager in a club, I would not even think of Kylian Mbappe because he's unbuyable, inaccessible. If anyone wants to try buying him, good luck!"
Mbappe is currently with France as the World Cup champions face Euro 2020 qualifying.
The forward scored in the 87th minute of France's first game of the international break, a 4-1 win over Moldova to open the qualifying campaign.
He was joined on the scoresheet by Antoine Griezmann, Raphael Varane and Olivier Giroud as France began qualifying with a lopsided victory in Moldova.
Next up for Les Bleus is a home match against Iceland on Monday.
PSG, meanwhile, currently sit atop Ligue 1, maintaining a 20-point lead on Lille despite the second-place side playing one extra match.
However, the club was eliminated from the Champions League at the hands of Manchester United as the pursuit of European glory will have to wait another season for the French side.
Next up for PSG is a clash with Toulouse on March 31 following the conclusion of the international break.