Landon Donovan facing a battle to make the USMNT World Cup team

Landon Donovan has been the face of United States soccer for more than a decade. Even when Tim Howard was at Manchester United and Clint Dempsey scored an incredible goal to beat Juventus and advance to a European final, Donovan was still in the American spotlight.

That spotlight may go out this summer, because Donovan may not even make the World Cup team.

While Howard rebounded from last year's struggles with one of his best seasons in years for Everton and Dempsey started off the MLS season as arguably the best player in the league, Donovan has struggled. He's looked slow at times, missed chances, made bad decisions and, all in all, looked entirely human.

For a player who is on the verge of breaking MLS's all-time goalscoring record and is the top goalscorer in U.S. history, mortality is not supposed to set in ever, and certainly not so quickly. But Donovan does look mortal, sometimes even bad, and Jurgen Klinsmann has made it clear that the 32-year-old won't be on the plane to Brazil because of the 57 goals he's scored in a U.S. shirt before. If he goes, it will be for the contribution he can make to the U.S. next month.

The problem for Donovan is simple -- age.

Donovan has admitted that his body isn't what it used to be. While he used to be able to run all day, every day, he acknowledges that on some days he just doesn't have it and that he needs more days off. That's not to say one of those days will be a match day, or even that he can't turn things up for games, but he can't be a star every day in training anymore, which is a problem. Klinsmann believes in competition, especially in training.

When Donovan has an off day in training, he makes it tougher for Klinsmann to pick him. When Donovan is slow to a ball in 7v7, he makes it tougher for Klinsmann to pick him. When Donovan loses his legs and misses a shot late in practice, he makes it tougher for Klinsmann to pick him.

An argument could be made that Klinsmann needs to be more considerate of an aging player and that training shouldn't be weighed as heavily for players he knows can turn it on come match day, but that's the problem Klinsmann faces right now -- Donovan hasn't proven that he has that switch.

Donovan has no goals and just two assists for the Galaxy this season. It hasn't been for a lack of opportunities -- he's been central to the LA attack and has the second most shots on the team -- but he's given the ball away, finished poorly and failed to beat players to the ball like he used to. He's been average by MLS standards, a far lower bar than the one Klinsmann has set.

To this point, Donovan hasn't shown that he can ease his way through training and shine in matches. How can Klinsmann justify picking him?

At this time, he can't, and that is what makes training camp so vital to Donovan. Nothing that Donovan has done in 2014 suggests he should be on the U.S. team, not with fringe players like Alejandro Bedoya, Terrence Boyd and Chris Wondolowski playing well for club and/or country, but Klinsmann isn't blind to what Donovan has done before.

Donovan has played in three World Cups, has scored in two of them and has been capable of disappearing for 89 minutes, only to make the one game-changing play in the 90th. All Klinsmann needs is a sign, any sign, that Donovan still has that in him somewhere.

The U.S. doesn't need Donovan to be as a starter for 90 minutes, or even for three matches. If he can be an asset off the bench, that will do. If he can start one match against a specific opponent and exploit a weakness, that will be good enough for him too. But can he do that?

Klinsmann has said that he views Donovan as a forward, a position which was clarified after Donovan played every Gold Cup match last season at the position. In that tournament, he scored five goals, but he did much more than finish in front of net. He made runs over the top, stretching the defense, and drifted wide to create width and open up space centrally. He wasn't a true striker by any means, but he was a forward who single-handedly changed the shape of the U.S. attack with regularity, confounded defenses and causing havoc.

A year ago, Donovan was also in much better form. He was playing faster, finishing better and tidier with the ball.

Then again, four years ago, Donovan was also blasting the ball at a Slovenian goalkeeper's head and pouncing on rebounds to set the U.S. into the knockout stages, creating some of the country's most memorable moments along the way.

A lot has changed for Donovan, and for the U.S. since then. He has taken a break from the game, traveled to Cambodia, and aged, all while the U.S. brought on a new manager that cares less for the team's elder statesmen then ever before.

There is still a place for Donovan on the U.S. World Cup team, but not the Donovan that has put on the Galaxy shirt this season. Now Donovan has two weeks to prove that the other Donovan -- the U.S. all-time leading goalscorer Donovan -- still exists within him. If he can't, he'll be watching the World Cup from his couch.