No World Cup can ever be won by relying on one player. So I think if Argentina rely on Messi alone, they will have to give up the hope from the World Cup. Everyone's concentration is needed there. Everyone has to play well. There is a lot of pressure on those who are good players. In that case, most of the time the result will not be good if those players are given extra pressure.
True, I still don't understand why people are talking so much about one or another player as if they were responsible for winning the Fifa cup.
In the case of Argentina, this is even more "relevant".
This year I'm very confident in Brazil, as they achieved extraordinary results in the rankings playing with a team of new players, still unknown and with different formations in each game, all without Neymar.
A good team is the one who will win this cup, I hope.