The two players, both now well into their thirties, continue to dominate at the top level and have broken countless records and filled many trophy cabinets between them. Obviously Guardiola knows Messi well, but on Wednesday he will be part of the opposition, while this season he has also come up against Ronaldo once again.
At his pre-match press conference in the build-up to the game at the Etihad, the Catalan coach was asked if he expects to see such a duopoly again.
“I don’t imagine [it will happen] as what these two guys have done will be almost impossible to imitate,” said Guardiola.
“Maybe I will see it but I don’t think it’s going to happen – scoring this amount of goals, the amount of titles both had done.
“It is so difficult. I think it is unique in history to find two players like Cristiano and Messi do what they have done.”
Few people know Messi’s abilities as well as Guardiola, but that doesn’t mean he knows how to stop him, as he acknowledged.
“It’s so difficult and sometimes when he has the ball he doesn’t know what he’s going to do – so imagine you have to know what he is going to do,” said Guardiola.
“I cannot tell the players what [Messi] will do, but hey, it happens with Neymar and [Kylian] Mbappe, with [Angel] Di Maria, with all the players up front in this team. Every player could be a complete star in any team around the world and all four are in the same team.
“But I am still glad and happy that [Messi] is still playing, at the level he plays and with the quality, so it will be nice to face him.”
Manchester City take on Paris Saint-Germain at the Etihad on Wendesday November 24 at 21:00 (CET).