Jose Mourinho is confident Lionel Messi and Cristiano Ronaldo can still meet in a Champions League final, despite both players nearing the twilight of their careers.

The world's best two players have yet to go head-to-head in the final of Europe's elite club competition, despite both of them having won the Champions League on multiple occasions.

Barcelona and Juventus were both among the favourites to reach the showpiece in Madrid this season, but were beaten by Liverpool and Ajax in the semi-finals and quarter-finals respectively.

And with Messi approaching his 32nd birthday, and Ronaldo already 34, Mourinho is disappointed at the thought of the duo never facing off in a Champions League final, though he acknowledged it may also be positive for a debate over which of the players is superior not to overshadow such a huge game.

"First of all, I think it's a frustration for all those who like football to never have had a [Champions League] final between the two," Mourinho told Eleven Sports.

"It was almost real many times, but it never happened. I always thought that it would be a big injustice to them, in the sense that everything would be centered on them and that one would come out holding on to the big ears cup and the other would come out with his head down.

"I always thought it would be a great injustice to have a duel between the titans of the two best players in the world in the last decade, for one of them to bow to the weight of defeat. That's why it's probably a good thing it never happened.

"Can it still happen? It could still happen. They're both in clubs that want to win. They don't hide that they want to win themselves. Of course it can happen."

Messi scored a sublime free-kick - his 600th club goal - in Barca's 3-0 first-leg win over Liverpool in the semi-finals, only for Ernesto Valverde's side to lose 4-0 in a remarkable second leg, with the Reds meeting Tottenham at the Wanda Metropolitano on Saturday.