The pair have scored 39 goals between them in all club competitions this season and are undoubtedly the headline acts for the match, but the Paris Saint-Germain striker is focused on securing his nation's place in Brazil 2014.
Ibrahimovic has been in stunning form of late and the 32-year-old is in buoyant mood ahead of Friday's first leg in Lisbon.
"I feel good, what matters is what I think of myself. I progress all the time and I'm 32, I've never played better than now," the Sweden skipper said. "[But] it's Sweden against Portugal - do not focus on two players. What matters is the collective, and to succeed we all need to do well."
The visiting side, which hosts the second leg on Nov. 19, will take confidence from its record against Portugal, having lost only three of the previous 15 meetings, but will be keen to break a run of three draws with the Seleccao.
Ronaldo will be key for Portugal as the team looks to qualify for its third consecutive World Cup, but has never beaten Sweden at home in seven attempts.
Erik Hamren's men suffered a 5-3 reverse against Group C winner Germany in their final round-robin clash, while Portugal is on a seven-game unbeaten run in its qualification campaign.
Portugal's only defeat in Group F was against eventual winner Russia, with Fabio Capello's men finishing a point clear to claim the automatic qualification spot.
Midfielder Miguel Veloso is the only new concern for coach Paulo Bento after he finished training with pain in his left knee.
Fabio Coentrao (ankle) and Joao Pereira (thigh) were injury doubts when the squad was announced, while William Carvalho would collect his first cap if used.
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