At long last, Jurgen Klinsmann named his 30 man preliminary roster for the World Cup. While there were a few surprises, the manager made the obvious picks. Here are the major topics of the most important roster of his tenure.

With defense full of holes, Tim Ream’s omission is most controversial

Ream’s omission, not Eddie Johnson, is the biggest snub. Unlike Johnson, Ream is playing well for his club and he addresses a weak position for the team. In hindsight, what killed the defender's chances was his absence from the recent U.S. game against the Ukraine. He was called up but missed out because of the recent birth of his first-born child. He has not played with the national team since 2011, and the game against Ukraine would have allowed him to reintegrate back to the team.

Despite that, it he shouldn’t have been left off. The decision goes against everything Klinsmann has preached about the importance of club form. Ream was consistent for Bolton all season long and was named the team’s player of the season. Additionally, he looked strong in four different positions: right back, left back, defensive midfield, and his natural position of central defense.

To compound the puzzling nature of his decision is that the backline under Klinsmann is the most pressing areas of need. There are lots of questions that don’t have a clear answer right now. Is Cameron a right back or a central defender? What is the central defender pairing? What is Klinsmann going to do about Omar Gonzalez who has struggled with the national team? Is Fabian Johnson left back, left midfielder, or maybe even a right back In fact, the backline is so unsettled that all four defensive positions remain a mystery just weeks away from the World Cup.

With so much up in the air, why not take Ream who has been playing well at every defensive positions? It would seem that riding the hot foot would make the most sense at this late stage.

Eddie Johnson’s cut shows that form and chemistry matter

By all accounts it was a surprise but not a stunner that Johnson was left off the team. He has never really scored against high level opponents and has had a woeful start to the season for DC United. Meanwhile, Aron Johnasson and Terrence Boyd each have over 20 goals this season at the club level, and Chris Wondolowski has three goals in his last two games for the United States.

Not to mention, people will wonder if the reports of his locker room rift with Seattle last year and his critical comments of DC United last week swayed Klinsmann into cutting him. I think it very well might have. Chemistry is important and the team will hope to grow together over the next six weeks. On the field they will have to fight for each other and a guy like Johnson calling out his teammates indicates that he could be a risk in a team environment.

Terrence Boyd is the opposite of Eddie Johnson

Part of the reason why Johnson was seen as expendable is that Terrence Boyd forced himself onto the roster. Off the field, Boyd has all the intangibles. No one is more enthusiastic about the U.S. team than Boyd. He gets along with his teammates, and it is hard to ever envision Boyd saying anything that would reflect poorly on his teammates.

Most importantly, on the field Boyd is playing well unlike Johnson. Boyd scored again on Sunday for Rapid Vienna and it was his 20th on the season. He finished with six goals in his last four games while Johnson has yet to find the back of the net in 2014.

Geoff Cameron is now looking like a central defender

Klinsmann brought in a lot of people who can play right back: Michael Parkhurst, Timmy Chandler, Brad Evans, DeAndre Yedlin, and even Fabian Johnson can all play the position.

If right back was clearly Cameron’s position for the U.S. team, why bring in so many others? The fact that Omar Gonzalez has struggled in central defense likely means that Cameron has to shift to the middle—where he grew up playing and still feels it is his best position.

I would say a starting central defense pairing of Geoff Cameron and Matt Besler is looking very likely.

Timmy Chandler has to finally live up to his potential

Timothy Chandler’s last time with the U.S. team was a dismal experience. He struggled mightily in a 2-1 loss to Honduras. While the game capped tied him internationally to the United States, Klinsmann was so unimpressed that he left Chandler out of all remaining qualifiers and friendlies in 2013.

Chandler has always been mysterious. He was not a highly touted youth player in Germany. He made his Bundesliga debut early in 2011 and was sensational. Former U.S. coach Bob Bradley brought him into camp that March and he was impressive in a draw against Argentina and loss to Paraguay. It appeared as if the U.S. found its right back for the next decade.

Then the relationship went south. He didn’t show up to the 2011 Gold Cup citing fatigue. He insisted that not wanting to be cap-tied to the United States was not a factor, few believed him since no other player used that excuse.

When Klinsmann took over the team in August, Chandler entered the equation but was playing mostly left back. After a series of uneven performances, Chandler stopped showing up for friendlies citing an unwillingness to commit. He finally rejoined the team at the end of the 2012 for a friendly against Russia and became cap-tied in the loss to Honduras.

That is the Chandler saga in a nutshell but it leaves out the anticipation among fans as to whether or not the talented Bundesliga player would show up for the U.S. team. The fact is that since his first two appearances for the U.S. team, he has either been injured, unwilling to show up, or mediocre when he has played.

The reaction from many fans is that he is going to walk in and take the starting right back position for the World Cup based on his impressive natural talent alone. It’s hard to see that happening. He likely enterers the camp behind others and he will have to excel to make the final 23. He’s on the 30-man roster but to the core of the team, he’s an outsider with a checkered past of unwillingness to commit. He has a few weeks to erase that doubt and integrate into a team he was never really part of.

Joe Corona is the most surprising inclusion

Most saw Julian Green coming into camp given the intense recruiting battle. Most also saw John Brooks involved as well since he ended the season well at Hertha and same with Terrence Boyd after his terrific end to the season with Rapid Vienna.

Joe Corona is a bit of a surprise and he likely took advantage of Sacha Kljestan’s inability to earn consistent minutes for Anderlecht down the stretch. Last summer at the Gold Cup, it appeared as if Corona was competing with Alejandro Bedoya for one spot. While Bedoya won out through very solid play, Corona was also good.

Looking to add more firepower, Klinsmann is bringing in Corona for another look and it is a smart move. Corona has an uphill climb to make the final but it is easy to see him fitting in with the core late into the cycle. He can play outside or centrally and his defense is also strong.