The Tottenham star was outspoken when he spoke to SVT Sport today after a light training session.
Kulusevski points out that Serbia is a world-class team and that they could have scored even more goals.
But he also believes that Sweden makes it too easy for the Serbs.
- We are eleven players in the team and we all have to help each other to defend ourselves.
We could have done better, especially in the corner where there are a few seconds left in the half.
It must be life and death, the ball must not go in.
We need a little more of that mentality, says Kulusevski.
However, Kulusevski believes that it is difficult to get that mentality just for one day.
He believes that Swedish football must get better at nurturing players with the right mentality.
- I think that the mentality must change already as a child, from when you are 15 years old.
I think we have to start much earlier, on the youth side.
Other countries are ahead of us right now.
- You have to want a lot more.
Here (in Sweden) it feels like it's a game, but out in Europe it's not a game, it's life and death.
If you don't get the ball away, the others score.
We really need to step up and make sure that young people have a better chance in the future.