The time for slip-ups and flat performances is officially over in the 2011 CONCACAF Gold Cup. No more second chances, and no more room for underwhelming efforts from the U.S. men's national team.

How They Got Here

The U.S. has lacked luster in through the first three matches, its first ever group stage loss bookended by two pedestrian wins. Despite the disappointments, the U.S. remains on track for a potential meeting with Mexico in the final, even if they have lost the co-favorites label along the way.

Group C Results - U.S.

Match Opponent Result 1 Canada W, 2-0 2 Panama L, 1-2 3 Guadeloupe W, 1-0 Not if the United States wants to have a chance to stop Mexico's seemingly inevitable road to the Gold Cup trophy.

The knockout rounds are here, and the United States will need to deliver its first complete performance on Sunday against a streaking Jamaica squad that finished the group stages a perfect 3-0, having outscored opponents 7-0.

Sunday's match is more than just an elimination game for the United States, it is the match that will likely define whether the 2011 Gold Cup was a success or failure. A victory against Jamaica could be the needed spark on a run to the final. And a loss? It would provide a damning and fitting end to a forgettable tournament for a U.S. national team

You could almost call Jamaica a favorite in Sunday's quarterfinal. That is, if you chose to ignore history. The Americans have never lost to Jamaica, going 9-0-8 in 17 meetings. The United States has also only lost one Gold Cup quarterfinal in the tournament's history, a penalty shootout loss to Colombia in the 2000 Gold Cup.

That track record won't matter much against a Jamaica side playing some of its best soccer in a decade. Theodore Whitmore has instilled confidence and discipline to a Reggae Boyz squad playing the type of attractive soccer reminiscent of the Jamaican team that last played in the World Cup more than a decade ago.

This new and improved Jamaica's defined by its speedy attackers, with Dane Richards, Demar Phillips and Luton Shelton spear-heading an offense that shifts from 4-3-3 to 4-5-1 with relative ease, pressing opposing defenses without leaving Jamaica's back-line exposed.

With Jamaica riding a wave of confidence, the United States will need to deliver a complete performance to avoid elimination. Against Canada, the Americans were good in the first half, but shaky in the second half. Against Panama, the United States started poorly and didn't recover until the second half. Against Guadeloupe, the U.S. team moved the ball well only to watch poor finishing result in a 1-0 victory.

If the America's going to start looking like a championship contender for the first time this tournament, they will need Clint Dempsey and Landon Donovan to start playing like the stars who helped lead the U.S.A. to success at the 2010 World Cup and 2009 Confederations Cup. Both players struggled against Guadeloupe, and neither has really stood out in the tournament.

How Dempsey and Donovan do against Jamaica will have the added storyline of their late arrival in Washington D.C. Donovan is attending the wedding of his twin sister on Saturday in California, while Dempsey is attending his sister's wedding in Texas on Saturday. Both players are flying private jets back to Washington on Saturday night ahead of the Jamaica match.

The United States will need Donovan and Dempsey to pressure Jamaica's wingers, which could in turn help the American central midfield dominate play in the middle of the field. The combination of Michael Bradley and Jermaine Jones has put in dominating performances against Canada and Guadeloupe and has the quality to shut off the supply lines for Jamaica's strikers.

The real question is how the U.S. back-line holds up against Jamaica's speedy attack; specifically, how centerbacks Carlos Bocanegra and Clarence Goodson deal with Jamaica's speedsters. The tandem enjoyed success against Guadeloupe, but Guadeloupe was missing top striker, Brice Jovial.

The fullback tandem of Eric Lichaj and Steve Cherundolo played well against Guadeloupe and boasts the speed needed to try and neutralize the likes of Richards, Luton Shelton and Demar Phillips. Lichaj's inexperience could leave him the more vulnerable of the two, though he showed against Guadeloupe that he is capable of defending well against a speedy winger.

Bob Bradley's biggest lineup question heading into the Jamaica match will be deciding who to partner with Jozy Altidore at forward. Chris Wondoloski struggled to make a real impact in the Guadeloupe match, and Bradley could be tempted to slide Dempsey up top, with Alejandro Bedoya and Sacha Kljestan making good cases for more playing time.

Regardless of the one or two lineup moves left for Bradley to decide on, the United States still heads into Sunday's quarterfinal as a team expected to win: a team expected to play much better than it has this Gold Cup. With a nucleus of players that helped the United States win the 2005 and 2007 Gold Cups, the United States can take a major step toward washing away the bad taste of an underwhelming group stage with a win on Sunday.

And a loss? A United States defeat would leave the U.S. national team eliminated, and the U.S. program in limbo, facing a far more uncertain future than could have been expected before the 2011 Gold Cup began.

In other words, anything less than a victory against Jamaica is unacceptable.

Ives Galarcep is a senior writer for covering Major League Soccer and the U.S. national team.