It is not impossible, it is possible that the mentioned team must be eliminated in the group phase. And the dark horse team drove unexpectedly, in fact this is what I look forward to at every biggest football party. Where countries that are not too favorites can talk a lot here. This is something that might happen in the current edition of the World Cup.
Who can be the dark horses this time, and do miracle like what Croatia did last time. No one really expected Croatia to qualify for the quarter-finals and they did the unimaginable by almost winning the trophy (back in 2014 it was Costa Rica). This time who will be the surprise package? I have made a list of teams who are capable of major upsets. Here is my selection - Senegal, Serbia, South Korea, Cameroon, Ghana, Wales and Australia. I am sure that one or more of these teams will feature in the semi-finals.