Mexico had a rocky qualifying process, which included a playoff against New Zealand to secure a spot. Under Miguel Herrera's command El Tri have strengthened, but there is room from improvement.
Herrera called 10 footballers from the 2012 Olympic squad that won the gold medal, eight who play in Europe and five more from local clubs.
Age-wise, this team has veterans, such as 35-year-old Rafael Marquez, and rising stars, such as 21-year-old Diego Reyes.
The warm-ups were key in defining the starting XI against Cameroon and also in understanding which areas need special care.
Does Mexico have what it takes to qualify to the knockout stage?
Herrera took over on October 2013 and has been using a 5-3-2 formation. He has favored this system since 2002, when he coached Atlante, his first managerial job.
Before his arrival, Jose Manuel de la Torre used to play with a traditional 4-4-2 or a 4-3-3. Both systems worked well, but El Tri took too long to get into the box.
Most of the play happened in the midfield, and breaking the rivals' defense was hard to achieve. Another thing that the team lacked was creativity, and the surprise factor was hardly present.
Herrera immediately worked on both issues and gave Mexico a completely new face.
The acceleration starts with the left back and right back. Those two are in charge of setting things in motion through the flanks.
Miguel Layun (LB) and Paul Aguilar (RB) work as flying full-backs. They support the defense but mainly join the attack. Layun has a powerful long-distance shot, while Aguilar is fantastic from inside the box.
The wingers have a lot of freedom, so they can either create plays or finish them at ease.
All in all, when Mexico combines speed and dynamism, it results in verticality, and that's the key weapon.
The way the squad opens spaces and creates plays from scratch is refreshing. Andres Guardado and Hector Herrera help Oribe Peralta and Giovani dos Santos in the attacking zone.
Both footballers are unbalancing and have the ability to liberate the midfield with passes and dribbles.
Mexico must take advantage of its verticality, which had not been present for quite a bit. That allows it to counterattack easily and hence surprise the opponents.
The 5-3-2 system can provide depth, speed and creativity, but it has also given Mexico a headache in the back line.
The defense has struggled under this formation because with Layun and Aguilar constantly joining the attack, the three center backs have to share the work in the box, and it gets especially tricky when the offense comes from the flanks.
The center of the pitch is key. There is only one central midfielder, and he needs to be very focused to cut off the attack before it finishes in the box.
A good solution could be pushing Rafael Marquez a bit to the front so he can provide support to the central midfielder.
Herrera tried it against Portugal, and it paid off. The Europeans couldn't do much through the center of the pitch, but they were dangerous through the flanks.
The defense needs to be tighter, especially in set pieces. Mexico has always suffered in this area, and with rivals such as Croatia, whose aerial game is super, and Brazil, which has great tactics and moves in free kicks and corners, it cannot waver.