"It's not a tranquil team, as the results haven't been those we want," winger Cristiano Ronaldo told reporters ahead of the Group One tie in Porto with Portugal in fourth place and Sweden fifth.
Portugal have taken five points from four matches, while Sweden have the same number of points with a game in hand. Denmark lead the group on seven points from three games, followed by Hungary and Albania.
Coach Carlos Queiroz wants his team to impose their creative style but recent results have exposed poor finishing and defensive frailties.
"We have to play in the Portuguese style, practicing attractive, modern football with movement, speed, fantasy and creativity. These are surely arguments which will be difficult for Sweden to counter," Queiroz told reporters.
Portugal's recent friendlies exposed more problems than style. The 1-0 win against Finland was secured with a penalty after the team failed to score from over 25 chances, while the 6-2 loss to Brazil featured errors from some of the world's most expensive defenders.
IBRAHIMOVIC SUSPENDED
Sweden's coach Lars Lagerback highlighted Queiroz's worries when he said: "Portugal didn't have the best of starts to the qualification and they must feel the pressure now playing at home, having lost seven points in the first four matches."
Zlatan Ibrahimovic's absence from the Swedish attack through suspension could be good news for Portugal but his replacement Henrik Larsson still poses a threat at 37.
Portugal's defence will be boosted by the return of Ricardo Carvalho from injury, and he will probably be joined in central defence by Bruno Alves with Pepe again moving into a role in front of the back four.
Hugo Almeida is favourite to start up front, with Queiroz hoping his height will avoid Portugal being at a disadvantage against the tall Swedes and that he can take advantage of service from Ronaldo and Simao or Nani.
Playmaker Deco has been called up, but an injury he picked up playing for Chelsea may prevent him from taking part. The absence of his passing ability would be a major blow for Portugal's plans to play at a high tempo.
Probable teams:
Portugal: Eduardo; Jose Bosingwa, Ricardo Carvalho, Bruno Alves, Duda; Pepe, Deco, Tiago; Cristiano Ronaldo, Simao Sabrosa, Hugo Almeida
Sweden: Andreas Isaksson; Erik Edman, Petter Hansson, Daniel Majstorovic, Mikael Nilsson; Samuel Holmen, Kim Kallstrom, Sebastian Larsson, Rasmus Elm; Henrik Larsson, Johan Elmander
Referee: Frank de Bleeckere (Belgium)
