The PSG star praised the Portuguese and says that Sweden will have to overcome a difficult hurdle if they want to compete in Brazil next year.
"Portugal are the favourites, but it will be two fantastic matches," he told his official website.
"We face a country with many skilled players who are performing on a high level.
"The play-off matches are like two finals. It's different compared to the group stage."
However, Swedish coach Erik Hamren wants his side to focus on their own strengths, and believes that they are strong enough to compete with the Group F runners-up.
"Many think that Portugal are at a top level, and I agree," Hamren told Radiosporten.
"But Portugal also have weaknesses. They finished the qualification campaign with a low amount of points.
"We need to produce fantastic displays if we want the chance to play in Brazil next year."