The U.S. women's national team doesn't often give up goals. Heading into Tuesday's game, they had only conceded goals in two matches all year. During last summer's World Cup, which they won, the defense went a whopping 540 consecutive minutes without conceding a goal.

But when the Americans gave up goals twice to Colombia on Tuesday, both on set pieces, a crack opened for doubt to set in. The Americans have arguably the best defense in the entire world, but did the match against Colombia expose an Achilles heel of sorts? Is defending set pieces a problem for the USA?

After the match, goalkeeper Hope Solo indicated the team was taking both goals seriously and intended to investigate how they happened. "We're going to learn from this, absolutely," she told reporters in Manaus. "We're going to watch a lot of footage on the set piece goals."

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Because of Solo's unusual unforced error on the first goal the U.S. conceded, it's difficult to know what to make of it. Kelley O'Hara, Becky Sauerbrunn and Ali Krieger had nearby Colombians covered and the U.S. defenders were all on the edge of the goal area ready to clean up any sort of rebound. If Solo handled it properly, the threat should've been quickly neutralized.

But the second goal against Colombia was a goal where the defenders, along with Solo, could've done better. Solo was surrounded by yellow shirts, and if Solo missed that punch, which she did, it could've easily been headed in rather than sailing directly into the net. The marking was poor.

"Part of our game plan was not giving them set pieces," Sauerbrunn said after the Colombia game. "We didn't want to foul them in bad areas and unfortunately both those set pieces came off bad fouls."

Solo would never be expected to have as much trouble as she did, but her teammates put her in very difficult positions with silly fouls. The first, from Megan Rapinoe, could've very easily been a straight red and it wasn't necessary because O'Hara and Sauerbrunn were in position to take care of the oncoming Liana Salazar. O'Hara committed the second foul by going after the player, rather than the ball, when the Americans had plenty of cover.

Of course, it's also worth noting that the Americans have been without centerback Julie Johnston. She has eight goals for the USWNT and all of them are from set pieces. Most of them have been scored off her head, too. In the absence of Abby Wambach, Johnston is slowly building a case as the new set piece specialist for the USWNT. When the U.S. beat Colombia in a friendly earlier this year -- their last meeting against Colombia before Tuesday's Olympic match-up -- the U.S. won 3-0 and two of the goals came from Johnston on set pieces. Her second goal was a quintessential Johnston goal here:

It works both ways -- Johnston is great at attacking on set pieces, and she's also good at defending them. Whitney Engen stepped up and did an excellent job at filling in for an injured Johnston against France and Colombia, but she couldn't match Johnston's set piece effectiveness because, well, few players can.

Still, it would probably be a stretch to point specifically to the Engen-Johnston swap as the cause for the USWNT's problems. Having Johnston in the mix likely would've helped, but Engen wasn't specifically responsible on the conceded goals -- and the Americans also looked particularly vulnerable to screens on set pieces against France, which were not quite the same as Colombia's goals.

In just the 16th minute against France, Wendie Renard broke away from Allie Long and went around a screen, with Long only reconnecting with her shoulder-to-shoulder as Wenard went up for the header. It was just enough to thwart Wenard's attempt, and it went off the crossbar and out for a corner kick. But on the very next play, a screen created confusion again as Americans lost their marks. Wenard created a pick as Amandine Henry beat O'Hara to the near post and got a head on the ball, albeit not cleanly.

If the USWNT will be watching film of set pieces, they would be remiss to not go back to the match against France, too. After all, the match against Colombia may have simply been a fluky game, first with an uncharacteristic unforced error from Solo, and then from a rare super-strike on the second goal. But if France managed to succeed on one of their set pieces, it could've been a very different result and path for the U.S. in this Olympics.

That said, France ultimately didn't find their goal and the USWNT has normally been solid on set pieces. The body of evidence the USWNT has left behind suggests set pieces are only rarely a weakness in defense and often a strength in the attack. But after the unusual turn of events against Colombia, it is something that opposition may be keen to try to test as a weakness, and you can bet the Americans will be working on addressing whatever went wrong.

"We know set pieces are crucial," Lloyd said after Tuesday's match. "The coaches have laid that into us... We gave up some set pieces goals which we know are vital to winning, tying and losing games. I guess it's my age, but you've got to find some silver linings and some positives, and I know this team can bounce back and we'll be ready going forward."

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