Christen Press said being able to shift from the team's normally aggressive attack to a more defensive stand is part of what makes the team ruthless.

"I would characterize it as optimism that we're going to win. But there is a ruthlessness to this team. And that's win at all costs," Press said. "That means tactically adapt in a way that we never have in four years. And you have to do that to win. ... It's incredible that we could change and still be so solid."

The United States and England have met just once before in the World Cup, a 3-0 U.S. win in the 2007 quarterfinals. But earlier this year the teams played to a 2-all tie in the SheBelieves Cup.

The Americans have been called brash and confident at this World Cup, from a resounding 13-0 victory over Thailand in the opener, to a shutout of nemesis Sweden to close the group stage, and finally to Rapinoe's raised arms in the victory over France. Neville added ruthless to the list.

Naeher explained that it's just a part of the team's DNA.

"That's the root of the U.S. women's national team, from back to the teams from 20 years ago," she said. "And that's always been the U.S. mentality and that's something that every veteran player has instilled in all the new players as we've come in. It's now our job to carry that through."