The winger fears a tough draw, while manager Didier Deschamps and forward Karim Benzema focused on the positives of France's victory on Tuesday.
Spain's win over Georgia on Tuesday ensured that Les Bleus finished as group runners-up, regardless of their comfortable 3-0 victory over Finland.
Didier Deschamps' men are expected to be in the second pot in the playoff seedings, meaning clashes against either Greece, Ukraine, Croatia or Cristiano Ronaldo and his fellow Portuguese teammates loom next month.
"The playoffs will not be easy games," Bayern Munich forward Ribery, who scored the opening goal against Finland on Tuesday, told TF1. "We will have to be men and make the best of both games, to do everything to go to Brazil. It's a World Cup. We hope to be able to avoid Portugal and Croatia."
Deschamps agreed with his winger's assessment that facing Paulo Bento's men would be far from ideal, but he also praised his side's performance in the final game of group stage qualification.
"We had the ambition to be the winner of this group, but it's good to see that we can also play this kind of game and score three goals, especially compared to what awaits us in November," Deschamps said. "I have no preference for the playoffs, but it is true that playing against Portugal, who have Ronaldo in their ranks, is different. We will switch our preparation to these games."
With his international goal drought behind him, Karim Benzema made it two goals in two games by scoring France's final goal against Finland and was pleased with how the match played out.
"Again tonight it's been fun to score, but victory is the most important thing," Benzema said. "It was a very good game and we must continue like this. I'll talk with Ronaldo about playoffs!"