"I have no problems sleeping at night," a relaxed Hamren told a news conference at the Olympic stadium in Kiev on Sunday.
"I don't lie awake watching videos or DVDs. And when I sleep I dream that we win, and when I wake up, I wake up happy."
When asked how he would spend his time on matchday before kick-off, Hamren added: "I'll hopefully wake up with a smile and try to train a little, try to improve the fat percentage.
"When the players rest... I'll rest too, and maybe I'll dream. That's the important thing with dreams - a wise man once said that if you're going to realise your dreams, you have to be awake.
"I hope in some way to experience us achieving our dreams."
Hamren said he had not yet decided if striker Johan Elmander, who has recovered from a broken metatarsal, will play against Ukraine.
"Elmander is OK to play. We'll make a judgement later as to whether he'll play or not - that's the next question."
Sweden captain Zlatan Ibrahimovic, in scintillating form for his country in recent games, told reporters he was aware of the high expectations on him but that it would help him rise to the occasion.
"I feel a lot of pressure. Wherever I came to play, even in the club team or national team I have had it," he said.
"[But] I like to play under pressure, it gives you something to play for.
"It's the first match for both teams, and clearly there can be some nerves to begin with, but I think both teams have plenty of confidence, both want the ball as much as possible."
The AC Milan striker declined to single out any of Ukraine's players as a particular threat, saying: "I don't see any individual as a key player - the whole team is made up of key players."
Often the target of abuse from opposing fans, Ibra also played down the possibility of racist chanting on the terraces.
"I think it's only football people who will be coming tomorrow.
"In my world, football is for everyone. It's a religion and everyone is welcome."
