CELLE, Germany - Angola's top priority before it faces Portugal in the first round of the World Cup will be strengthening its defense. And the United States will be its first test.

Angola, one of four African teams making its World Cup debut in Germany, will play its final warmup match against the Americans on Monday without fans or media present.

On Friday, the Black Antelopes lost to Turkey 3-2, giving up a late goal.

"It's true that there was a problem of defense. They defended badly, so the defenders are the most to blame," Angola coach Luis Oliveira Goncalves said. "But it's not just the defenders. The team as a whole needs to concentrate harder."

Angola, considered the weakest team in Group D, has lost all its World Cup warmup games. The team also struggled at the African Cup of Nations earlier this year, losing to Cameroon and Congo before being eliminated despite beating Togo.

Hardly a strong way to prepare for the toughest competition in the sport.

"The coach is concentrating a lot on defense because that's the most concerning aspect of our game at the moment," defender Delgado said Sunday.

Goalkeeper Joao Ricardo said there is still time to improve, however, particularly against the United States in Hamburg.

"It's important for us not to suffer in this game," Ricardo said. "When people lose, they are never happy."

U.S. assistant coach Glenn Myernick thought it was important for the Americans to see another opponent before their June 12 opener. Their last warmup was May 28.

"There's no substitute for just playing and playing against some different faces besides your teammates," Myernick said. "It will add a little bit to the match fitness situations, and anytime you can play, it's better than any training session we can put on.

"To go from our last game against Latvia to our first game against the Czech Republic would be too long a time without a competitive situation. Let's be competitive, but let's not be foolish in our challenges."

After playing Portugal in Cologne, Angola will face Mexico and Iran. But the players acknowledge that playing their former colonial rulers holds its own challenges.

"For us, Angola, to face Portugal, it's true we feel a bit anxious," midfielder Edson de Jesus Nobre said. "But at the time of the game, we'll be ready to face them. And in football, sometimes, weaker teams beat stronger teams."

Angola and Portugal have met twice, with four Angolan players sent off for brutal tackles and dissent the last time they played five years ago in Lisbon. That game was abandoned with 20 minutes remaining.

"We are preparing ourselves for the game, but Portugal has world-class players. It's hard to say where their weaknesses lie," Nobre said.

"We are going to try and surprise the world," Ricardo said.