Ronaldo and Manchester United parted ways after an explosive interview in which the Portugal star said he felt "betrayed" by senior figures at the club, while claiming to have "no respect" for manager Erik ten Hag.
The five-time Ballon d'Or winner's exit has led to much discussion over his next club, with Ligue 1 giant PSG one of the teams rumoured to be interested in making a move for the 37-year-old.
But PSG president Al-Khelaifi ruled out any potential deal, although he did speak highly of the former Real Madrid man.
"He's a legend, he's a star," Al-Khelaifi said. "The footballer, I admire and love him as a player and professional. A fantastic player.
"He's 37 now – he's doing amazing. But every single club wants to sign him too. The problem today for us is we have the position [filled] – his position – so it's not easy to replace the position that we have with him.
"It would be impossible, honestly, for us."
One of those players PSG have in Ronaldo's position is Kylian Mbappe, who is currently leading the goalscoring charts at the World Cup in Qatar with France.
Mbappe was heavily linked with a move from PSG to Real Madrid earlier this year, but the 23-year-old instead signed a bumper new contract to stay in the French capital.
Al-Khelaifi believes it was vital to keep Mbappe at PSG, saying: "For me he's a very top, top player and a top human being, professional.
"For me it was really key he stayed and he didn't leave for free. That's another important point.
"As I always said, I always trusted him, trusted his family because we created something of a special relation with the player and them and that's why… he's Parisian, he's French and he's proud always to be in France."