Structure occupies a rather unique place in the United States - Mexico rivalry. Most of the focus usually falls on the long, rancorous history between the teams, the collection of players on the field or the stakes at hand in the buildup to kickoff. Those factors naturally rise to the fore in such a contentious fixture, but the tactical preferences also play their part in how these derby matches unfold.

Some meetings - think the round of 16 encounter in Jeonju to send the United States through to the quarterfinals of the 2002 World Cup - turn on managerial decisions. Others - think the 2011 CONCACAF Gold Cup final won by Mexico at the Rose Bowl - shine a spotlight on specific personnel issues. The rest serve as a means of contrasting the fundamental operating principles of the two sides and revealing how to accentuate or blunt those strengths.

The impending clash at Crew Stadium on Tuesday night offers an opportunity to incorporate all three of those tenets. Rampant uncertainty within both camps provides an opening for Mexico coach Luis Fernando Tena or United States coach Jurgen Klinsmann to impose a plan capable of procuring the desired result.

Tena naturally faces the more difficult of the two challenges in the wake of the 2-1 home defeat to Honduras on Friday. Jose Manuel de la Torre's post-match exit paved the way for the 2012 Olympics mastermind to ascend to this potentially poisoned throne. The brief interlude between matches leaves Tena with scant opportunity to stamp his own identity on a struggling team in desperate need of a result at Crew Stadium.

De la Torre opted for a 4-3-3 formation in his final match in charge, but Tena might have to ponder a straight 4-4-2 setup to accommodate Javier Hernández and Oribe Peralta. Significant questions swirl around Hernández's match fitness (he has played less than a full half of competitive soccer this season), but Tena finds himself in a position when El Tri desperately need a result, and their talisman to help secure it. If he opts to risk Chicharito from the start, the shape must change to accommodate him.

The usual operating principles away from home won't evolve much in either instance, though. Mexico want to obtain possession with high pressure (a rare bright spot in the past two matches) and play swiftly into the wide areas to pull apart the American back four. Tena could make changes to introduce more pace to test the US fullbacks, with Javier Aquino and Andres Guardado as potential alternatives. The defensive structure will entrench a bit - expect more caution in central midfield (especially with Gerardo Torrado banned) and from the fullbacks - ahead of this road affair, but Tena admitted he cannot enact sweeping changes to this group given the compressed time frame.

Klinsmann enters this match with no such luxuries, with Michael Bradley ruled out with an ankle injury and Jozy Altidore, Matt Besler and Geoff Cameron suspended. The absences of Altidore, Besler and Bradley drastically change the composition, if not the structure, of the outfit and heap pressure on other players to rectify the evident concerns.

Bradley's omission - as painfully shown during the 3-1 defeat at Costa Rica on Friday - looms as the most critical alteration in the usual 4-2-3-1 setup. The AS Roma midfielder drops into the right positions every time and links the American play through midfield with his willingness to shuttle between defense and attack. Jermaine Jones doesn't operate with the same discipline in either department. Jones' carelessness in possession - a genuine problem in San Jose - might prompt Klinsmann to turn to Kyle Beckerman instead of the more positive Mix Diskerud to provide a bit of cadence and solidity in the center of the park with Bradley unavailable.

Retaining possession assumes additional importance given and Mexico's efficiency on the counter and the issues at the back and up front. Poor work in the middle third exposes a somewhat rickety U.S. back four stripped of its most consistent performer. Besler's replacement - likely recent arrival Clarence Goodson - must remain positionally sound. Not only to cover for Omar Gonzalez's ill-fated willingness to stray, but also to track the clever movements of Hernández and Peralta.

Altidore would have proven particularly useful in this match as a direct option (look at the problems Carlo Costly posed for Diego Reyes on Friday night) if the American midfield struggles to cope with Mexico's ardent pursuit. Clint Dempsey operated as the primary forward on Friday night, but he isn't a natural operator in that position. If he continues to lead the line (and he likely will, given Klinsmann's preference to deploy Eddie Johnson on the left), then the Americans will look to combination play between Dempsey and Landon Donovan in front of and through the Mexican defense to conjure opportunities.

Dempsey's placement represents just one of the many adjustments poised to contribute to the outcome in some fashion. Both teams enter this match with apparent vulnerabilities on the field and, in Mexico's case, in the changing room. The result - at least in this edition of the rivalry - will favor the side most capable of adapting its personnel and its structure to mask its own flaws and prey on the weaknesses of its enemy.