World Cup 2018: Lionel Messi looks stressed, which is a real worry - Pablo Zabaleta column

The happiest I saw Lionel Messi when I played alongside him for Argentina was in 2012 - he scored a hat-trick against Brazil in New York, and he played the whole game with freedom and a smile on his face.

His body language was completely the opposite before the Croatia game on Thursday. To see Leo looking so stressed and unhappy at this World Cup was a real worry.

He is my friend as well as my former team-mate and I felt really sorry for him. It is very unusual to see him like that, but it was a sign of what was going on in his head.

At times like this, there is a huge pressure on him because people expect too much, and for him to do everything for the national team.

I was not surprised he struggled, in what was a disastrous defeat for us. As a player myself, I know that if you go into a game and you don't really enjoy it then it is very difficult to play well.It was not just Leo, though, it was a poor performance by the whole team. We are very lucky that we still have chance to go through to the last 16 by beating Nigeria on Tuesday - but I am not sure it will happen.

We will have to perform much better than we have done in our first two games and show the right attitude and much more desire.

Football is a collective game and everyone needs to improve - not just Messi.

This time, Argentina coach Jorge Sampaoli has to set up with the right formation and the right players, and follow a plan.