FOR MANY OF THE players on the first ever United States U-21 roster, it was a chance for top prospects to remain engaged with the federation ahead of the 2028 Olympic cycle or for those already recent veterans of youth national teams to remain on the radar of full national team for next cycle. Most of the players have been viewed as top prospects since their mid teenage years and have come through the country’s top traditional developmental channels.

Santiago Castaneda, however, is one of just two players making his first ever U.S. debut at any age level (the other being Gerardo Valenzuela). Now in his second season as the starting defensive midfielder for current 2.Bundesliga leaders SC Paderborn, it was a call-up for which he’d been striving.

During the camp Castaneda, a Tampa native, celebrated his 21^st birthday and as a late 2004-born player, he just misses the cutoff for the 2028 Olympics. But for him, this is a unique opportunity to get himself on the radar of the federation for either Mauricio Pochettino or whoever coaches the national team following the 2028 World Cup.

“Since this is my first camp, it's just kind of easing through it,” Castaneda told ASN from the U-21 team camp. “I am learning from the guys here and the coaching staff, getting feedback from their perspective, and meeting all these players. Hearing their stories and their backgrounds is something cool. Individually, I am just trying to perform well to show I'm capable of playing at a high level and maybe get an opportunity with the first team in the next cycle.”

When Castaneda arrived in camp, he was only familiar with Damion Downs from the 2.Bundesliga last season, and Thomas Williams from his days in Florida. But he had no personal connection with anyone. But he insists integration into the squad has gone well.

“All the guys are super nice,” Castaneda said. “Most of these guys just came from the U-20 World Cup and know each other, but they don't treat me like I'm an outsider or anything. Everyone wants to know more about me, and they ask me questions, and the same other way around. It's a really good group of guys.”

Castaneda was informed of his call-up to the U-21 team not long before the roster was announced publicly.  He admitted he was surprised and was unsure of where he stood with the federation having aged out of youth national teams without ever having been invited to a camp.

When he began to break out last season in the 2.Bundesliga, he was aware that Paderborn had reached out to federation to lobby for his inclusion but was unsure if that was going to lead anywhere.

“Last year I had a really good season individually and with the team as well we came in fourth place just three points behind promotion for the Bundesliga,” he explained. “I talked with my agent and with the manager at the time at Paderborn and they said that they contacted U.S. Soccer speaking about me and I knew there was some connections there but I never knew exactly when I was going to get a call up or if I ever going to get a call up.”

What is most striking about Castaneda’s development path is that it did not come through MLS academies, youth national teams, or college soccer. Instead it came through channels such as high school soccer, club soccer in the Elite Club National League (ECNL), and the USL academy level.

When he was 15, he was playing for Tampa Bay United which is now in MLS Next but was called the DA Development Academy at the time. But the sport was becoming a grind and he recently was offered a scholarship to attend Tampa Preparatory School, a top private school in the area. At the time, the DA had a rule that said you could not play high school soccer along with DA soccer.

In the end, Castaneda opted to walk away from Tampa Bay United so that he could play for Tampa Prep. He also continued his club soccer with Florida Premier SC of the ECNL which allows players to play with their high school teams. In his junior year, he led Tampa Prep to the state championship with a 21-0 record. In 2022, he joined the academy of the Tampa Bay Rowdies while retaining his eligibility for college.

“It was a very tough pathway for me,” Castaneda told Soccer America in a 2024 interview. “Growing up, all I thought about was a professional career. But when I was 15, I transferred to Florida Premier. It was sad because I was MLS Next, which they say is the best league in the American system. For my parents, education was a huge thing. It was a big decision. But honestly, that was one of the best decision I've made in my life. If I didn’t attend that school, I don't think I would be where I am today.”

“It was a private, top tier school,” he continued. “With MLS Next or when it was called the DA Development Academy -  it was getting very serious and the love for the game wasn't as strong. Once I was playing high school soccer, I tell everyone it was just fun. There's no pressure. You're just playing for fun and you're playing with the guys that you have classes with. It is not the best level of soccer, but it brought joy back to the game for me.”

Shortly after accepting an offer to play soccer for the University of Michigan, Castaneda given the opportunity through Capelli Sport to be part of a Talent ID squad to play games in Denmark. There he was identified by scouts in Germany.

While education was very important to Castaneda, he could not turn down his dream of professional soccer – which also runs deep in his family. He is the son of two parents from Colombia. His father, Carlos Castaneda, is from Medellin and was a former professional player in the Colombian leagues. His mother is from Cali and is big supporter of America de Cali.

Castaneda first signed with MSV Duisburg in Germany’s third tier. Despite the team’s struggles, he was picked up by SC Paderborn after one season.

At Paderborn, his career has taken off. Last season, at just 19, he earned the starting job and played over 2000 minutes as the team finished fourth. This season, however, under a new coaching staff, the team currently sits first and is carrying an eight-game winning streak.

While last year Paderborn surprised many by being in the promotion race until the final weeks, this season the club and its fans are hopeful of being able to pull it off despite there being bigger clubs in the league.

“For sure, there's pressure for us,” Castaneda said of the pressure now on Paderborn. “I think there’s even more pressure for the bigger teams. You have Hertha Berlin, Schalke, Hannover, Nürnberg - big names that usually you will see in the Bundesliga. For us, being at the top of the table, not many people in Germany like it, because they don't think Paderborn deserves to be in the Bundesliga. You see Schalke in second place, so a lot of people are happy about that - a big team coming back to the Bundesliga.”

“We don't have quite so much pressure because our fan base, they're really supportive,” he continued. “The media focuses a lot on those big teams. We're under the radar right now. But we put that pressure on ourselves to stay on top of that table, trying to fight for promotion. We're really united, the mood right now is very good, and we are hungry for more.”

For Castaneda, the next order of business is concluding the U-21 camp against Serbia after the team’s 1-1 draw against Denmark. But even as he returns to Germany this week, this camp has been one of the most emotional moments of his career.

“It means so much to me,” Castaneda said of the call-up. “When I first found out, I was very emotional, especially with my family. I grew up with my mom and dad and my brother. And since I was a little kid, this is a dream that, not only for me, but for everyone else, that we always thought about.”

“I've always wanted to be called up,” he added. “I think this is the timing where I deserve the call up and I've been fighting really hard for it. It means everything to me, honestly. I'm able to play for Columbia as well. Either way, I was wanting a call up from either one. But growing up and being raised in Florida and America, this means a little bit extra.”