Portugal on Sunday lost the chance to qualify automatically for the World Cup.
Portugal gave away a one-goal lead to lose 2-1 to Serbia in a Group A World Cup qualifier.
Renato Sanchez had opened the scoring for the former European champions, but Dusan Tadic equalized in the 33rd minute of the game.
Aleksandar Mitrovic then came off the bench to grab a 90th-minute winner and complete a remarkable comeback for Serbia.
The victory ensures Serbia takes the top spot with 20 points.
They have three more points than second-placed Portugal, who only needed a draw to finish on top on goal difference and qualify.
Instead, Ronaldo and his teammates will head into the March playoffs with the other group-stage runners-up to try to reach Qatar 2022.
Reacting, Ronaldo, in a post via his Instagram account on Monday morning, said, “Football has shown us time and time again that, at times, it is the most winding paths that lead to the most desired outcomes. Yesterday’s result was tough, but not enough to get us down.
“The objective of being present at the 2022 World Cup is still very much alive and we know what we have to do to get there.
“No excuses. Portugal heading to Qatar.”