The U.S. captain says that weather conditions and the need for only a draw affected the team's performance against Germany in their Group G finale.
The U.S. needed only one point to secure a spot in the round of 16. But after conceding an 55th-minute goal to Thomas Muller and Germany, the Americans needed some help from Portugal to advance.
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"You know in the back of your mind that a draw gets you through," Dempsey said. "It's not like a normal game because there are a lot of factors that play into it."
The Stars and Stripes got off to a slow start in rainy Recife and struggled to push forward against FIFA's second-ranked team. It wasn't until stoppage time that the Americans had any real scoring chances, but by then it was clear they were going to move on.
Cristiano Ronaldo scored in the 80th minute to help Portugal defeat Ghana 2-1 in a game that was played at the same time. The Portuguese also finished the group with four points, but the U.S. entered the day with a huge edge in goal differential.
"We're not happy with the result in terms of losing the game, but I think we deserve to go through to the next round and we're excited about the possibility of getting to the knockout stages," Dempsey said. "The fact that we were able to get out of a very difficult group shows the belief that we have in ourselves."
The U.S. only had four shots against the Germans, with none on target. The team was also dominated in possession, holding the ball for only 33 percent of the match.
But Dempsey partly blames poor weather conditions that flooded streets in the area, preventing several fans and family members from making it to the stadium, for the U.S. looking rusty throughout the match.
"It was weird conditions because of the rain and not having a proper warmup," the captain said. "On the field you're having to go behind the goal and not getting able to do a possession game and not being able to get shots on goal. It was just a weird preparation.
"And also in the back of your mind you think about your family not being able to make it to the game because of the traffic and everything, and you just want to make sure they're safe. There were just a lot of factors going into today's game that made it a difficult one for both teams."