Portugal, who reached the finals courtesy of a play-off win over Bosnia-Herzegovina, must battle against Brazil, Côte d'Ivoire and Korea DPR for a place in the last 16 of the competition. Five-time winners Brazil are the favourites for the tournament while African powerhouses Côte d'Ivoire boast players of the calibre of Didier Drogba, Yaya and Kolo Toure, Emmanuel Eboue and Salomon Kalou.
And it is Portugal's clash with the Ivorians that Ronaldo believes could be crucial, with the two nations starting their Group G against each other in Port Elizabeth. "Winning the first match will be very important," said Ronaldo, who could come up against Real Madrid team-mates Kaka and Marcelo as well as former Manchester United companion Anderson in the Brazil side.
"We have been handed a very complicated group. It's going to be difficult but I'm happy to be able to face my team-mates and friends. Football is always complicated. You cannot have regrets. We have to play well to win. We are motivated to face the best teams."
If Portugal claim a top-two berth then it is possible they will come face to face with Iberian neighbours Spain in the last 16. That could pit Ronaldo against more of his Madrid team-mates in Iker Casillas, Sergio Ramos, Xabi Alonso, Alvaro Arbeloa and Raul Albiol.
Asked about the prospect of maybe facing the European champions so early in the FIFA World Cup, Ronaldo added: "If we get through and we play Spain I would be happy. They are a great team, but right now my only concern is the group stage. It will be a good sign if we face Spain. It will mean we've got through."