The World Cup's group stage is over and the U.S. women's national team won Group F without allowing a goal. The Americans scored more goals (18) than their opponents had shot attempts (nine). The statistics were skewed, of course, by the attention-getting 13-0 drubbing of Thailand.

What does it reveal about the team heading into the round of 16?

For an answer, consider this utterly meaningless moment, late in the game against Sweden. The U.S. led 2-0 with nothing left to play for, in the fifth minute of seven stoppage-time minutes in the second half. Left back Crystal Dunn halted a desperate Swedish attack, two quick midfield passes found Tobin Heath, and Heath picked up her head and immediately launched a wild attempt at a 60-yard pass to spring Mallory Pugh down the right of the Swedish defense.

There was no reason for an attack. Most teams would have settled for a slow, run-out-the-clock dribble toward the opposition corner flag. Yet Heath turned and mashed the gas pedal.

There's your answer: There's no off switch with this edition of the U.S.

If the 2015 team was cautious, still finding its stride at this point in the tournament — that squad played out a cagey 0-0 draw with Sweden in the group stage — this team has no such reservations. It's full go, all the time.

Next up is Spain (11 a.m. Monday on FS1). Despite Spain's storied soccer history, it's one of many countries where the women's game is still extremely young. Its national team reflects that, with only one player over age 30. The U.S., by comparison, has 11. This is only Spain's second World Cup appearance, and only recently have some major Spanish clubs begun to invest in women's teams. Chief among them are Barcelona and Atletico Madrid. Real Madrid still does not have a women's team, which gives you a sense of how seriously the women's game is taken there.

All of this is not to say that Spain will be a pushover. The Spanish ran powerhouse Germany close, losing 1-0, and drew with China in the first round. In the past year, Spain has tied Germany, defeated Brazil and lost 1-0 to the United States. Striker Jennifer Hermoso is its player to watch; she led the Spanish League with 24 goals for Atletico Madrid this season.

It won't be an easy road to the final for the U.S. women. If they defeat Spain, they'll likely face host France in the quarterfinals, then probably England or Australia in the semifinals with a win. The Americans have struggled to beat all three sides over the past few years.

Not that history will affect this U.S. squad. If the group stage taught us one thing, it's that the U.S. doesn't look back and has only one setting: Full speed ahead.