The U.S. women’s soccer team’s quest for an Olympic gold medal just got a whole lot tougher.

U.S. star forward Abby Wambach broke two bones in her left leg in a full-speed collision with a Brazilian defender on Wednesday night and will miss the entire Olympics. It’s a devastating blow for the U.S. and for Wambach, its best player, who was aiming to score her 100th international goal.

The U.S. won the exhibition game in San Diego 1-0, but the team’s real test will be to find a replacement for Wambach, 28, who has led the team in scoring at the last three world championships (Olympics and World Cups).

Wambach’s injury was painful to watch. In the 32nd minute of a feisty game that could hardly be called a friendly, Wambach took a pass from defender Heather Mitts and played a give-and-go with forward Amy Rodriguez. The return pass from Rodriguez led Wambach by a hair too much, and in a friendly like this one some players would have shied away from the 50-50 ball.

But not Wambach, whose competitive fire burns deep. She went in at full speed just as Brazilian defender Andreia Rosa came in at full throttle herself. And in a move that Wambach no doubt wishes she could take back, she wound up and kicked the ball with her left foot. Wambach’s leg struck Andreia Rosa’s left leg on her follow-through with such force that it broke Wambach’s left tibia and fibula, the main bones in the lower part of the leg. 

It wasn’t a dirty play, just a freak mishap that can take place when neither player is willing to give any quarter. Yet there’s no denying that Wambach’s adrenaline was running high: she had already been involved in several skirmishes with Brazilian defender Renata Costa, who’d earned a yellow-card for knocking Wambach down just three minutes before Wambach was injured.

Wambach was scheduled to have surgery on Thursday to insert a titanium rod in her left leg. Her recovery is expected to take around three months.

The scoring pressure for the U.S. will now be squarely on two forwards: Natasha Kai, the 25-year-old tattoo-covered Hawaiian who has scored 12 goals in 2008 (including the game-winner against Brazil on Wednesday), and Rodriguez, the 21-year-old newcomer known as A-Rod who led USC to last season’s NCAA championship.

But neither player has the track record of Wambach. Just yesterday I crunched the numbers to see how Wambach’s scoring rate compared to the greats in U.S. women’s soccer history. And when it comes to goals per 90 minutes, Wambach is at the top of the list for U.S. players who’ve scored at least 50 times:

Abby Wambach     .935
Michelle Akers       .904
Cindy Parlow         .791
Mia Hamm             .687
Tiffeny Milbrett      .675
Carin Gabarra        .578
Shannon MacMillan .519
Kristine Lilly          .412

There will be some critics who wonder why Wambach risked an injury by playing in a friendly that was the team’s last game before the Olympics, who wonder why the U.S. scheduled two games against Brazil, a bitter rival that has been known for overly physical play—and has been competing without risking stars Marta, Cristiane and Daniela, who are with their clubs in Sweden.

But those same critics were the ones who complained that the U.S. men didn’t schedule tough enough opponents right before World Cup ’06. And while it’s fair to argue that the Brazilian women can be hackers, it wasn’t a dirty play that injured Wambach. Instead it was Wambach’s refusal to play at anything less than full-speed. And it’s awfully hard to criticize someone for that.

Now we’ll see what the rest of this team is made of in China. In the wake of Wambach’s injury, do you think the U.S. still has what it takes to win the gold medal?