The perfect record in group play can be called perfection, and the two matches without allowing a goal can also be called dominant. Yet, as much as the US women's national team set a new standard by going 3-0 in Olympic group play for the first time in team history, Tuesday's 1-0 victory against North Korea felt something less than overwhelming

Yes, the Americans will head into the group stage unbeaten and favored to capture a potential third straight Olympic gold medal. Nonetheless, for a second straight match, team USA struggled to dispose of an opponent that should have been easier to put away.

Ultimately, the United States has done what it set out to do. Beating France in the opener was no easy task, and the struggles that a team can endure when facing opponents playing to keep the score down are well known. The fact remains that for the second straight match, the US national team had trouble with a team much weaker than the opponents that lie ahead in the later rounds of these Olympics.

The question now is whether the three days between Tuesday's victory and Friday's quarterfinal date against New Zealand will be enough time for a tired United States side. Will they be able to regain enough energy to play like the unstoppable attacking force we saw against France?

Pia Sundhage had better hope so after starting most of her starters in all three group matches. As much as we have heard about this US team being the most fit team in the World Cup, they are still human and showed signs of wearing down on Tuesday. Players like Lauren Cheney and Megan Rapinoe looked worn down against the North Koreans, with Rapinoe leaving Tuesday's match at halftime. Without her boundless energy providing the spark to the US midfield, the American attack faded in the second half as Alex Morgan and Abby Wambach were left starved for service.

You can blame Sundhage for the rotation issues, but it should be noted that whatever plans she had for rotating players and spreading around minutes took a serious hit when Shannon Boxx suffered a hamstring injury against France. Boxx's injury reduced Sundhage's options in midfield and added more fuel to the questions surrounding Lori Lindsey's exclusion from the national team.

Though fatigue looked to be an issue on Tuesday, there were plenty of positive notes from the American victory against North Korea. The defense looked sharp against an opponent that provided a tougher test than Colombia, with Amy LePelbet rebounding well from her struggles against France and Rachel Buehler playing her best game in some time.

We also saw Morgan and Wambach continue to be a dynamic duo, with Morgan setting up Wambach's goal with a clever move and pass to finish off an impressive passing sequence that started with a Rachel Buehler pass out of the back.

Wambach's first half goal was the seventh in her career at the Olympic games, extending her lead atop the US all-time list for career goals at the Olympics."It was awesome," Wambach said after the match. "So many US fans came for this game specifically. It's a dream come true for a lot of us. It's unbelievable to have gotten a goal."

Similarly impressive, Heather O'Reilly rewarded Sundhage's continued faith by showing her trademark quality and boundless energy. O'Reilly, who underperformed in her start against Colombia, certainly looked like the best midfielder on the US team in the match, showing us all that she's worthy of a starting eleven spot,

The efforts of O'Reilly, LePelbet and Buehler had to be the most satisfying and encouraging for Sundhage. All three players were likely the ones she was going to have to give some serious thought to benching heading into the quarterfinals. Now, all three have shown that they are capable starters.

On Friday, it will be up to those players who showed tired legs against North Korea to recuperate and be ready for a match against yet another underdog in New Zealand. It is an opponent the Americans will be expected to beat. After two straight matches at less than their best, and with the semifinals and a potential final sure to provide significantly tougher challenges, team USA should be looking to hit their stride before tougher tests arrive on the scene.

"It wasn't the best game in terms of being organized defensively and covering our angles," said United States goalkeeper Hope Solo. "But we got a win. We swept our group. You're going to have one of those games.

"We all knew the energy was a little bit low. But we're happy. We made it out."