The Mexicans will be bearing in mind some of the poor results they have suffered in the last couple of years, in particular a humiliating 7-0 hammering at the hands of Chile.
But the squad have stuck together and built a competitive outfit for the World Cup.
"I think it had an impact on us and now we are very much united having gone through very difficult moments," midfielder Andres Guardado told a news conference on Friday.
"We have been able to build a team that is today competitive."
Mexico have three points, while South Korea have zero after losing 1-0 to Sweden in their first match.
Coach Juan Carlos Osorio insisted that his team would not be complacent, however, underlining South Korea's tactical nous.
"I hope that we're not going to rest on our laurels and take our foot off the gas. We know all too well that in football, things can change overnight," he said.
"Everybody is healthy and we are totally prepared to face a great opponent tomorrow.
"All the players are focussed. We did not come to the World Cup just to beat Germany."
And South Korea will be a tough nut to crack, Osorio believes.
"We're going to be playing a very robust opponent, even if we have all the chances to win," he said.
"They have a lot of strength, they are versatile, most of their players can play in different positions and in different systems. They have three possible formations."
It means that Mexico do not exactly know what kind of team they will be facing at the Rostov Arena.
"They depend on their coach and what he might think of us," said Osorio.
(Reporting by Julien Pretot; Editing by Hugh Lawson)
