Ronald Koeman towed a diplomatic line in response to a question about Lionel Messi and Cristiano Ronaldo's standing in world soccer. 

Speaking ahead of Tuesday's Champions League game against Juventus, the Barcelona coach said it is "not nice" to argue over which of the "incredible" duo is the better player.

The pair, who have won 11 Ballons d'Or between them, are set to go head-to-head at Camp Nou for the first time since the Portuguese joined the Serie A giants from Real Madrid in 2018.

“It’s fantastic that these two players have been so long at this top level in the world,” Koeman told beIN SPORTS in Monday's pre-game press conference.

“They are the best players, in my opinion, in the last 10-15 years. Being successful all this time is incredible. It’s a great compliment to those players.

“They are different, but they have incredible stats about scoring goals, hat-tricks, about winning prizes.

“It’s not nice to say who is better because both are incredible, I admire both players because they gave us so many nice evenings with great goals, with great titles. Let’s hope we can enjoy them tomorrow night.”