THROUGHOUT 2015 SHANE O'NEILL had his sights set on playing an important role with the United States U-23 team—the Olympic qualifying squad. Everything was tracking well earlier this month and the 22-year-old put on a good defensive display in the team’s 1-0 loss to England's U-21 team on Sept. 4.

But then everything unraveled quickly due to a bizarre turn of events. Shortly after the game against England, O’Neill began to suffer headaches and dizziness. He returned to Belgium, where he had just joined top flight club Royal Mouscron-Péruwelz, and focused on his recovery.

“It was all starting to click,” O’Neill told American Soccer Now from Belgium. “After the England game, I had a problem with my head and now there is growing concern with head injuries. But the thing is that I didn’t take a knock, which was strange. It was weird, it wasn’t a concussion-like feeling. So after the England game I was shut down for the camp. I went back to Mouscron to relax for 4-5 days to get my head straight.”

After a few days he trained with his new club and even played in a reserve team game. But then the problem resurfaced. And by then it was time for U.S. U-23 head coach Andi Herzog to make his final Olympic qualyifying roster decisions—which would require Herzog to engage with Royal Mouscron-Péruwelz to a release. 

Due to the seriousness of head injuries and the lack of a clear diagnosis, O’Neill was left off the roster. Only a few days later did doctors determine that the problem was not very serious but rather an inner-ear infection that could be treated with antibiotics.

Both sides are certainly frustrated with how everything played out. Herzog had singled out O’Neill as one of the team’s best performers after both the England game this summer’s U-23 tournament in Toulon. And O'Neill is struggling with the fact that he will not be lining alongside his U-23 teammates next week.

“It was a nightmare to be honest,” O’Neill said after taking a deep breath to collect his thoughts. “It was very disappointing, obviously. If they found out about it earlier, I would have been released for qualifying. All I needed was an antibiotic.

"It’s very frustrating to not be part of it because I’ve been part of the team since the beginning. This whole year, it has kind of been my main focus. Andi is one of those coaches that, for whatever reason, just instills a ton of confidence in me. I feel like I am playing my best when I am with that team. Even in the England game, I felt defensively it was a very good performance.”

The Irish-born, Colorado-raised O’Neill will instead be staying up late in Belgium to watch his U-23 teammates attempt to qualify for the Olympics without him. He is optimistic that the Yanks will earn a spot in Rio de Janeiro next year and believes their chances “are quite good.” He also singles out Jordan Morris as being a huge addition to the team.

Should the U.S. advance to the Olympics, O’Neill is looking forward to the chance to reclaim his spot on the team. The central defender recently left the Colorado Rapids, his club since 2012.

While he enjoyed his time in MLS, O'Neill decided to leave due to the changing circumstances at Colorado, which has been struggling all season and currently is in last place in the Western Conference. His playing time with the Rapids decreased significantly and he was only seeing occasional minutes.

The opportunity to move abroad was unusual: O’Neill was initially bought by Apollon Limassol in Cyprus but was loaned to Royal Mouscron-Peruwelz, a club with strong ties to Apollon Limassol. Now he is just happy to have a fresh start in a league where he believes he can succeed.

“It wasn’t necessarily the league," O'Neill said. "It was the situation. I was in was a tough situation. Then this opportunity came for me to come to Europe. I thought this was the right time and right opportunity. It was a good chance. My time with Colorado had come to an end. They were trying to focus more on veterans than younger players. I definitely wanted to try something new and needed a chance of scenery.”

He has that now, even though he is still recuperating from the inner ear problem. O’Neill expects to be back to 100% in about a week, at which point he can push to make an impact with Royal Mouscron-Peruwelz, currently in 12th place in the Belgian top flight.

“This league really suits my style of play,” O’Neill continued. “It’s a physical league but it’s not overly physical. I am a good physical centerback but it’s not really my game. My game is mainly on the ground. I like to play out of the back and that is very much what this league is about with technical and possession-oriented players. The league is very tactical and that is one thing I can tell after being here for just a few weeks. It will be a great learning experience for me with all the little details.”

O’Neill is excited to be part of the new wave of American players attempting to establish themselves abroad. As he leaves MLS behind, he appreciates how the league prepared him to make the move abroad and believes many players in MLS would be successful in Europe.

“I look at some of the players in MLS and they would do extremely well here,” O’Neill said. “People’s perception of MLS here is so off, in my opinion. The standard of MLS is very good. People here see it as a place where the older superstars go to retire. But they don’t see the likes of Matt Besler and Kei Kamara and other guys who are high-quality players in their prime. I think MLS is very comparable to the Belgium league in terms of standard and it’s only going to get better.

“Some here are like, ‘I want to play here until I am 34 or 35 and then move to MLS.’ I nod my head but that’s just not the reality of MLS. You can’t just go there on holiday and do well. It’s about as much hard work as anything else. I think people will start realizing that more and more.”

Brian Sciaretta is an American Soccer Now columnist and an ASN 100 panelist. Follow him on Twitter.