THE CURRENT WORLD CUP has seen its share of unexpected developments, from Spain and England shockingly being eliminated after two games to one-time also-rans like Costa Rica and Algeria advancing to the knockout stage.

And then there’s the United States national team and its defense, which fans and pundits alike worried would be the team’s Achilles’ heel—particularly given the high-caliber attackers they’d be facing in the Group of Death.

This concern was a combination of the unit’s inexperience at this level—for the first time since 1990 none of the center backs on the U.S. roster had previous World Cup experience—along with some shaky performances in tune-up games earlier this year.

And while there have been some hiccups, for the most part the central defenders have been up for the moment. And none has been better, or more consistent, than Matt Besler. The Sporting Kansas City center back has been a model of consistency, though what he is most pleased with is his team’s, and the backline’s, fighting spirit.

“The way we battled, the way we defended, was great,” Besler told reporters in Recife, Brazil, after the U.S. held Germany to one goal in a "successful" 1-0 loss.

Of group play, he added, “It was a grind for sure, tough physically. A lot of ups and downs emotionally but that’s what it’s about. All three games took a little bit of a toll on everybody. The great thing is now we’re going through. And we can find that extra level now that we’re into the knockout rounds, and the great thing is we get an extra day” to rest.

Unlike the other center backs the U.S. has used in Brazil, there has been no signature spectacular play from Besler. There have been no game-winning goal like Jonathan Brooks scored against Ghana, no series of blocked shots like Geoff Cameron had in the same game, and no last-second lunging tackles or headers to break up an attack like Omar Gonzalez had against Germany.

Despite battling a misbehaving tight hamstring that caused him to miss the second half against Ghana, Besler has used his trademark smarts and composure to be in the right place at the right time and anchor a unit that has exceeded pre-tournament expectations and is a large reason why the U.S. has advanced to the Round of 16, where it’ll face Belgium Tuesday.

“It’s funny, there were a lot of doubts cast early about that area of the team but that’s one area of the team that’s been solid,” said Notre Dame coach Bobby Clark, who is both a former Scottish World Cup player and Besler’s college coach. “People talked about his inexperience but I suppose the only way you get experience is to play. Matt’s more than paid his way. If he didn’t do that they wouldn’t be where they are today.”

While lacking that one defining moment, Besler’s steady-as-she goes approach has not gone unnoticed by one of his predecessors on the U.S. World Cup back line.

“I think he’s been fantastic,” said former central defender Eddie Pope, a veteran of three World Cups for the U.S. “We’ve played, obviously, three very difficult teams and he’s had a very good game every time. To do that in your first World Cup is not easy but he’s been outstanding. As a former center back, and a U.S. soccer fan, we all had high hopes but also some questions, for our center backs.

"But he’s stepped into those shoes and done very well.”

Pope noted that with Besler leading the way, the U.S. defense has both exceeded expectations and outperformed some other big-name defenses.

“What he and the rest of them has done shouldn’t be discounted. This World Cup there’s been some poor defensive performances by big teams with some big-name players from the best clubs in the world. But for all intents and purposes, [the U.S. has] been pretty good and certainly exceeded expectations. I’m extremely proud.”

An academic All-American at Notre Dame who graduated a semester early with a 3.52 GPA in pre-med, Besler’s lack of signature plays, according to Clark, come from using his brain.

“He’s very fast, one of the fastest in the squad, actually," he said. "But he doesn’t look fast because he’s always thinking and rarely puts himself in position where he has to chase. If you’re a smart player you never seem to be chasing and he’s usually been in the right spot at the right time.”

Pope, now the No. 2 official at the MLS Players Union, has been impressed with Besler’s composure in the World Cup pressure cooker.

“Number one, he’s very calm, he doesn’t ever really panic,” he said. "It’s one of those intangibles, you don’t always see it because there’s a little bit of a nuance to it. But he has it. He’s very measured. He’s intelligent and his distribution is good, good in the air. Those are great attributes as a center back and he’s using them all right now in the World Cup, which is when it needs to click and it’s clicking for him right now.”

Besler’s composure was born out of the chaos that comes from being the oldest of three active, athletic boys growing up in Overland Park, Kan., a Kansas City suburb.

“Our house, there was always a lot of activity, lots of different sports and very hectic and crazy because we were so active,” said youngest brother Nick Besler, a rising senior at Notre Dame, which he helped lead to an NCAA title last fall. “But even though there was that kind of chaos and we drove our Mom crazy, Matt was always focused and organized and not easily distracted. He’s organized off the field and I think you see that same approach to his game on the field. He’s always thinking a play ahead.”

At six-foot, Besler is the smallest of the U.S. center backs, and growing up he was always a bit on the small side. “We just grow late in our family,” Nick Besler said. “Matt probably was still growing through his junior year (in college).”

As a result, Besler was never a U.S. youth national team player and had to contact Notre Dame to express his interest in the school. His junior year of high school he was participating at a tournament in Arizona and Clark dispatched his son Jamie, a former MLS player and then an assistant at New Mexico, to evaluate Besler.

“Matt was a lanky kid with a good stride who covered a good amount of ground," Jamie Clark said. "He made good decisions and was an honest (central midfield) player that didn't do any one thing that ‘wowed’ you. But over the course of 90 minutes he did all the little things to help his team win,” recalled the younger Clark, who eventually coached Besler as one of his father’s assistants at Notre Dame. Clark is now soccer coach at the University of Washington.

“Once you got to work with him every day, a few things stood out. He was quietly very confident and this allowed him to become a very composed central defender,” continued Jamie Clark. “You watch his first touch and entry passing and it's as good as it gets. He sees the channels very well and disguises his passes, which allows him to be very effective in build-up. That said, he understands pressure and knows when to be safe with the ball. He's just a very intelligent young man and this shows up on the field with his play.”

Besler, and the U.S., will need all of that intelligence and composure against a Belgium team that features some dynamic attackers—like Romelu Lukaku and Eden Hazard.

Besler is undaunted.

“We’ve shown we have a really good foundation, able to fight for every ball," he said. "That gets us a long ways but we all understand have to play better. Belgium’s another very talented team. We’re going to have to keep the ball better than we did today. Obviously everyone is so excited and proud of what we accomplished.

"But we’re still hungry.”

Brooke Tunstall is a veteran journalist who has covered Major League Soccer since its initial player dispersal draft. Follow him on Twitter.