Just minutes after the ecstasy of Clint Dempsey's goal in the first minute of the World Cup, the hearts of American fans sank.
While chasing down a ball at full speed along the left sideline, U.S. striker Jozy Altidore lowered his head to control the ball. He quickly grabbed the back of his thigh and fell to the ground. He was carried off the field by stretcher.
"I was sprinting and I felt something, and we'll see what happens," Altidore told reporters after the match. "Of course it was tough for me, I was crushed. I knew right away I couldn't continue, so that was probably the worst feeling."
A spokesman for U.S. Soccer soon revealed the injury to be a strained left hamstring. Altidore missed the remainder of that win against Ghana and the subsequent draw against Portugal. As the American team plays one of its most important matches ever against Germany on Thursday, the 24-year-old Altidore will again watch from the sidelines.
On Tuesday, U.S. men's national team head coach Jurgen Klinsmann announced that his striker has not recovered enough to battle his former German side.
"Jozy is recovering really well," Klinsmann said. "He's doing a tremendous job. Our medical staff is on top of it. This game comes still too early for him, but we're working on him. We're getting him back in this tournament, as we said. So once this game is done - hopefully successfully - we'll have a good chance to have him back then in the team."
Sadly, such a disappointing injury is not a new experience. Altidore suffered a hamstring injury in the quarterfinals of the 2011 CONCACAF Gold Cup and missed the semifinal and final match.
Altidore referenced his 2011 hamstring injury and hopes that history wouldn't repeat itself this time.
"Hopefully I can recover quicker," Altidore said. "We'll have to see, but it felt similar and hopefully I can recover and get back on the field."
Hamstring injuries are among the most common injuries in football, baseball and, yes, soccer. Altidore now demonstrates one of the most challenging aspects of these injuries. A player with a history of hamstring injury has a dramatically higher risk for suffering another one.
Studies on hamstring injuries paint a gloomy picture. Athletes with a prior hamstring strain are between two and six times as likely to suffer subsequent strains, often within the first few weeks after returning to play. Even years after the injury, they are twice as likely to suffer a hamstring injury than a player who hasn't suffered one.
Why exactly these injuries are so likely to recur is unclear. Many experts argue that these injuries can heal with scar tissue formation and reorganization of the muscle that could make the athlete more susceptible, even years later.
Regardless, most agree that rushing a player back to play without adequate rehabilitation significantly increases his risk of reinjury. A soccer player must be able to run without pain, but he must also regain full strength and functional ability.
If the U.S. team doctors and Klinsmann hurry Altidore back before he is 100 percent, they risk the forward pulling up lame again and missing the rest of the tournament.
Dr. David Geier is an orthopaedic surgeon and sports medicine specialist in Charleston, For more information about soccer injuries and other sports medicine topics, go to his blog at drdavidgeier.com.