If I would ever get a chance to ask from world famous Messi or Ronaldo than the only question would be -- do you know all the Soccer fans want you to play like super heros in every match. Do you have that on your mind while playing and how do you cope up when you are unable to perform well in an match. After all they are human too. 
We are talking about two of the most experienced footballers and I don't think that they can be put under pressure. They have been playing at the highest level for almost two decades and by now they can handle pressure better than anyone else. But the expectation from fans will be there as a burden. These players do have superhuman status in front of the eyes of football fans and sometimes people forget that they are human and are prone to making mistakes. But this tournament is very important for them, because it is going to be the last world cup for both these players.
I'm not so sure about that.
It's not the same to play for Barcelona, Real, Juve or PSG, where you play with the best footballers in the world and everyone can solve the game, or to play in the national team where you have weaker teammates and everyone is waiting for you to do something on your own and solve the game.
Also, it's not the same to play for a club or for your national team, when you represent your nation.
I think that even Messi has a special pressure because all the fans in Argentina compare him to Maradona and until Argentina finally wins the title of world champion, Maradona will always be considered better and bigger than him.