I know what you're thinking, this one's obvious. It is, however, perhaps the most important matchup of the game, so it's worth discussing. How will the slower U.S. center back pairing of Clarence Goodson and Carlos Bocanegra handle the pace and movement of a player like Chicharito? Knockout stage games against Guatemala and Honduras have shown that he can, to some extent, be contained, but even then he has popped up to score a goal, including Mexico's game winner against Guatemala.
Particularly shocking about both goals Chicharito scored in the knockout stages is that he was left criminally unmarked for both strikes, and therein lies the task for the United States defenders. As plenty of Premier League defenders have realized, though, marking Chicharito often feels like a futile task, and there is no reason to think that U.S. defenders will have it any easier. Let's not get too carried away though, there have been matches where Chicharito hasn't scored. OK, just one in this tournament against Costa Rica and Mexico won 4-1 anyway. So, the question is, how do you contain him and limit his influence, especially when you have two fairly slow center backs?
The apparent and most effective solution has been to cut off the service to him. Honduras succeeded in that sense by deploying a five man midfield that effectively hampered Mexico's creative abilities for much of the game. Still, Chicharito managed to still get into dangerous positions and receive those balls, and only some uncharacteristically poor finishing prevented him from netting a goal in the first 90 minutes. Bob Bradley has favored a five man midfield with Juan Agudelo up top against weaker opponents in Jamaica and Panama to good effect, and with Mexico's passing ability, there is little doubt that he will go with a similar shape. (It should be noted that, although using slightly different personnel, the U.S. also had a similar shape in their 1-1 friendly draw with a technically superior Argentina side.)
Still, the point stands that Chicharito will receive the ball in a dangerous position at some point and the U.S. center backs will have to work out a solution. The first and foremost task for Clarence Goodson and Carlos Bocanegra is to remain disciplined, positionally and emotionally. With Giovani Dos Santos likely roaming between the midfield lines and Chicharito, the temptation will be there for one of the U.S. defenders to get too aggressive in defending him, getting pulled out of position and allowing Chicharito space to make his runs. Furthermore, Chicharito will always beat Goodson and Bocanegra for pace, meaning that they will have to be spot on all night on knowing when to step and keeping themselves between Chicharito and the U.S. goal.
On the other hand, Goodson and Bocanegra do have an advantage in that Chicharito isn't the biggest striker, meaning given the right positioning, they should be fairly comfortable in the air. That's where Aldo De Nigris comes in for Mexico. He has a more physical style of play than Chicharito, and with the probable absence of Andres Guardado in the Mexico lineup, could very well see more playing time and perhaps even a start. His knockdowns and hold up play make Mexico's attack more versatile and present a different set of problems for the U.S. backline. De Nigris, however, is clearly not as fast as Chicharito and in many ways provides a simpler matchup for the U.S. center backs, though that doesn't mean it will be easy.
Chicharito and the Mexican attack will without a doubt present the toughest test this U.S. defense has faced in the tournament, but the U.S. can take heart in the fact that the 2-0 defeat to Panama aside, it has not conceded a single goal. Furthermore, Bocanegra and Goodson have both been here before (even if Goodson might like to forget his last Gold Cup final), and Chicharito has not, and games like these can often be decided by who keeps coolest under pressure. Confidence and experience will not get the U.S. all the way to a clean sheet though. For the U.S. backline, discipline, organization and tactical awareness will be paramount in keeping the best player in CONCACAF off the scoresheet. For Mexico, it will be all about keeping cool under pressure and punishing the United States for any defensive slip-up, because there won't be many.