ONE OF THE MAJOR THEMES of the 2015 Major League Soccer season will be on full display Sunday during MLS Cup: the success of teams that have largely elected to build with U.S. coaches and U.S. talent.

On one side will be host Columbus Crew, headed by Gregg Berhalter and featuring rising stars like Ethan Finlay and Wil Trapp. On the other will be the visiting Portland Timbers, led by Caleb Porter and the league’s newest—and perhaps most intriguing—American player.

Darlington Nagbe, who received his U.S. citizenship in September and his first U.S. call-up last month, had past shown flashes of his potential since being drafted second overall in 2011. But in the second half of this season, with Porter implementing a tactical switch, Nagbe has seen his game truly take off.

“I’ve tried to float him wide where he’s not really wide,” Porter told American Soccer Now. “I’ve tried him as the No. 10, but he seems to sometimes not find space or get freed up there.

“But at D-mid, almost a No. 8, box-to-box mid, it seems like he came to life. I always worried that if we played him there, we’d be too light and wouldn’t be defensively balanced enough, but funny enough, he was winning balls through his athleticism and his ability to read the game and positioning. But the biggest thing is that he was just getting on the ball all the time. That is what he ultimately wants to do.”

It was also what Porter wanted Nagbe to do, and it had been a long time coming. Porter had coached Nagbe in college at Akron. He’d coached him with Portland with 2013.

But despite all of that, he hadn’t been able to find out where, exactly, Nagbe’s best position on the field lay. Now, with Portland having lost only once since Sept. 20, he believes that he has.

Nagbe, 25, agrees.

“I think that role puts me into a position where I can get more touches with the ball and help dictate the play a little bit more as opposed to the wing,” he said. “When you’re not touching the ball, you’re not going to enjoy it as much. My touches have grown, so my confidence has grown even more.”

In the end, it was a position that had been in his blood all along: While Nagbe denies its connection to his positional switch, his father, Joe, had been a star box-to-box mid for the Liberian national team for more than a decade.

Nagbe was himself born in Liberia as a civil war broke out and ripped through the country. He would eventually flee with his mother and brother to a refugee camp in Sierra Leone before they were able to rejoin Darlington’s father, who was playing in France at the time for SAS Epinal. Joe would go on to play for clubs such as OGC Nice, Lugano, and PAOK Thessaloniki, and Darlington in time would develop similar ambitions.

“Growing up in a different country where soccer is the biggest sport, it’s a different experience,” Nagbe said. “It’s a sport that’s played at school, at lunch, at recess, before school, after school. You get that sense of wanting to be a professional player.”

But while Nagbe’s roots in the game date back to his time overseas, his growth primarily took place in Ohio, where his family moved for good in 2001. The one constant in a life full of changing countries, languages and cultures was soccer.

“When we first moved here we spoke English, but it’s different coming here and going to school,” Nagbe said. “There is slang, but you don’t really catch on to it and you can’t understand everything. But just like anywhere around the world, when you roll the ball out there, it’s just fun. You get back to doing what you know and what’s natural. Once that happened, my brother and I finally felt at home. It was just something to look forward to every single day.”

On a recruiting trip for Akron, Porter first saw Nagbe as an early teenager while playing for the Cleveland Internationals. Porter was blown away, he said, from the minute he saw Nagbe warm up.

This weekend presents another defining moment for the long-lasting duo, which in 2010 helped Akron to its first national title and now will have a chance to lift Portland to its first major trophy. But it may not even be the biggest one of 2015 for Nagbe, who made his U.S. debut against St. Vincent and the Grenadines in the United States’ first 2018 World Cup qualifier.

“It definitely adds confidence to you when the coach said he’s looking to bring in new talented players and you’re one of the guys he thought of to bring into the team,” Nagbe said. “It’s definitely a huge compliment. Hopefully there are more and more chances to come.”

Porter, who knows Nagbe as a player better than anyone, recalled how easily he raised his game when moving from the Internationals to Akron to, ultimately, Portland. And the coach believes that the challenge of the national team will only lead to the next stage in Nagbe’s development.

“One of the reasons why I was so excited to see Darlington getting an opportunity with the national team is that certain players will only make jump if they are in an environment that will challenge them to raise their game,” Porter said. “Darlington is one of those players where, no matter the level, he has the athleticism and most importantly the technical speed and the tactical capacity to jump to any level.

“I firmly believe that tomorrow if you threw him in a training session with Barcelona that he be able to fit in no problem. Would he be the best player? No. But would he be out of place technically and tactically? No. He would raise his game.

"That is what Darlington does.”