Karlström's first child is expected to be born around the departure date for North America, but he hopes the baby will arrive before then.
I hope so. But as long as everything goes well, I'm happy, Karlström says.
I just have to try to be there for my girl as much as possible.
A similar situation applies to Gabriel Gudmundsson, who has already prepared himself for the fact that he will miss the birth.
"I have very mixed feelings. Unfortunately, I will miss it, in all likelihood," he says.
Recently, midfielder Yasin Ayari has also become a father.
Sweden begins the World Cup against Tunisia on June 15.