The Seleccao succumbed to a late Eden Ben Basat goal after a mistake from goalkeeper Rui Patricio, meaning that a draw for Russia in Azerbaijan on Tuesday will be enough to see them clinch top spot in Group F after they beat Luxembourg 4-0.
While Portugal can still mathematically snatch the automatic spot away from Fabio Capello's men, Ronaldo conceded his side are almost certain to be facing another play-off for a major tournament, having also navigated the process to reach World Cup 2010 and Euro 2012.
"It's not a drama to be in the play-offs," the 28-year-old told A Bola. "It's become normal, it's not a surprise because that's what has happened to us in recent years.
"[Automatic qualification] is mathematically possible but not up to us. We must be content to play the play-off.
"Hopefully, we'll now get a bit of luck and not get a complicated team. The only team I wouldn't like to face is France."
Portugal spurned a number of chances before Patricio's kick landed straight at the feet of Ben Basat for an easy equaliser, with head coach Paulo Bento refusing to place sole blame on his goalkeeper for the result.
"Mistakes are made collectively," Bento said after the match. "In the second half we started just as well but after 10 minutes we had more difficulties to move the ball, we were more inaccurate and ended up penalised for a situation that can happen.
"We tried to react but more with the heart, using a more direct game that we are not prepared for.
"We ended up being penalised for a mistake."