The United States will face fierce rivals Brazil on Saturday in a titanic quarterfinals clash at the 2011 FIFA Women's World Cup.

The US were flying high after its first two group matches against North Korea and Colombia but came crashing down in a 2-1 loss to Sweden on Wednesday. Head coach Pia Sundhage and her team must quickly put that experience behind them in order to prepare for what will be their biggest test yet. The US's World Cup dreams are on the line.

Here are 10 keys to United States success this weekend.

#1. Be wary of Brazil's two holders

The US has struggled against teams that utilize both holding midfielders and layered midfields. Sweden's defensive midfielder Nilla Fischer helped clog up the center of the pitch in Sweden's surprising 2-1 win in the US's final group stage match. Shannon Boxx has been the team's appointed defensive midfielder but has looked overwhelmed and ineffective.

Brazil will likely use both Formiga and Renata Costa to marshal the midfield, which will pose a challenge in Sundhage's flat 4-4-2 system.

#2. Get Heather O'Reilly involved

The 25-year old outside midfielder had an excellent outing against Colombia that included a spectacular arching goal in the US's 3-0 win. O'Reilly sustained a groin injury during the match, however, that required her to miss the US's final group stage match against Sweden. Although O'Reilly isn't necessarily a defensive player, her cutting runs and link-up play gives the US an added dimension in attack, and thus, makes it more complicated to defend against. The Sky Blue FC midfielder provides an invaluable and unique service in midfield; one that must be highlighted to carve into Brazil's wide areas.

#3. Beware of the first 10 minutes of the second half

Brazil exploded in the first 10 minutes of each group stage match. Momentum changing goals came in the 54th minute against Australia, the 46th and 48th against Norway, and the 49th and 54th against Equatorial Guinea. The lightning quick blitzkriegs have had devastating effects on their opponents and have permanently turned the tide in Brazil's favor. The US must proceed into the second half with extra caution.

#4. Fight fire with fire with speed up top

Brazil will try to torment the US's back line with the blinding pace of Marta, Fabiana, and perhaps Erika. The US has speed in fleet footed forward Amy Rodriguez, and she must work to get in behind Brazil's unique three-back defense. Heather O'Reilly must also be a key figure in this task. That will require accurate distribution from the midfield. Both teams must prioritize breaching their opposing defenses first.

#5. Sort out the issues at left back

Converted center back Amy LePeilbet has been the subject of scrutiny after three underwhelming performances at left back. North Korea and Sweden both sent speedy wingers flying down the flank and LePeilbet struggled to cut off their runs or crosses. As Shek Borkowski mentions , her task hasn't been made any easier by Lauren Cheney's newfound presence at left outside midfield. LePeilbet had a nightmare of a game against Sweden in which she drew a penalty for denying a goal-scoring opportunity before deflecting a free kick into her own net.

Auxiliary left back Stephanie Cox is an option, particularly If Sundhage feels LePeilbet's confidence has plummeted. Cox is a better distributor of the ball than her Boston Breakers teammate but lacks the defensive qualities that has made LePeilbet such a stellar central defender. Still though, will Sundhage elect to make the change on the eve of such a big match?

#6. Make sure the attacking players are defensive-minded

Brazil's unique 3-4-3 system employs a midfield that can be at times be occupied by as many as seven players. The team's sweeper, Daiane, has helped spur the attack from a deep-lying position while Brazil's brilliant attacking duo of Marta and Cristiane sit directly behind central forward Rosana and can branch off into the flanks. Compound that with Brazil's pair of defensive midfielders and two wingbacks and you get a numerical disadvantage in the middle of the park. That will mean that forwards Abby Wambach, Amy Rodriguez, and outside midfielders Lauren Cheney, and Heather O'Reilly will need to occasionally track back and lend central midfielders Shannon Boxx and Carli Loyd a helping hand.

#7. Have clear communication at the back

Communication between center backs Christie Rampone and Rachel Buehler has been found to be lacking at times. The central defensive unit has struggled to close down players that run directly at them and have relied on last-ditch tackles to clear the danger. Both players seemed to lose track of one another in the Sweden match as they were bludgeoned by their opponents' blistering pace. A clear understanding of each others' defensive duties will be key.

#8. Don't be enchanted by Brazil's bursts of brilliance

Brazil's flamboyant fleet of attackers are capable of producing jaw-dropping goals and mesmerizing moves. They've been known to have a petrifying effect on defenders. Australia's center backs and defenders stood flat footed as Rosana volleyed home the majestic game-winning goal in the team's first group match. Brazil performed similar feats against both Norway and Equatorial Guinea as both teams' respective defenders were caught admiring Brazil's skill on the ball. The US has a history of doing that as well, namely in the team's 4-0 defeat to Brazil in the semifinals of the 2007 FIFA Women's World Cup. The US can't afford to be bamboozled by Marta and company again.

#9. Assert your authority from the opening whistle

Brazil are late-bloomers in that they tend to have tentative starts and epic finishes. Brazil have looked disorganized and hesitant in the first halves of each group stage match. Only one of Brazil's seven group stage goals has been scored in the first half.

The US is also prone to slow starts. It was able to recover against North Korea in its opening match but failed to mount enough of a comeback against Sweden.

The team that can take charge of the momentum in the first half could be well poised to have an advantage in the second.

#10. Have faith in the bench

The US has been known to derive some much needed inspiration from its substitutes. Twenty-two-year-old striker Alex Morgan cemented her place on the national team with her game-winning, stoppage time goal in the first leg of the US's World Cup playoff against Italy last November. Lauren Cheney stepped up and scored a marvelous goal from long-range off the bench in the team's 1-0 victory against Mexico in the team's World Cup send-off match.

Cheney is likely to get the start on Saturday, as will winger Heather O'Reilly, if she proves to be match fit. That will mean that Megan Rapinoe will return to the bench. The 26-year-old outside midfielder has been impressive coming on as a sub. She scored off a lovely solo effort against Colombia and almost had another one against North Korea. The US bench may need to be counted on once more.