Hungarian international Nemanja Nikolic was one of the most outstanding strikers in Chicago Fire history. He won the MLS Golden Boot in 2017 and was named to the All-Star team.

During his time in Chicago, he trained with quality players such as Bastian Schweinsteiger and Dax McCarty. But he also trained with a 14-year-old boy who now wears Chelsea's famous blue jersey. His name was Gabriel "Gaga" Slolina.

JENKIFOCI: Do you remember the first time you heard Gaga Slonina's name at the club?

NIKOLIC: Slonina first trained with the first team around 2018, when he was just 14 years old. Chicago Fire coach at the time, Veljko Paunovic, and sporting director Nelson Rodriguez were constantly striving to support the development of youngsters and eventually integrate them into the first team. They looked out for local talent because the hearts of the fans could be won by home-grown youngsters. Slonina was one such local talent. Even at the age of 14 or 15, he was praised by the goalkeeper coaches. Looking strictly at his qualities, everyone expected him to have a great career. They knew he was a real asset to the club.

JENKIFOCI: What memories do you have about him?

NIKOLIC: I can only say good things. His physique was like an adult even then. And he had great instincts. He closed the angles very well in one-on-one type of situations. Of course, you could see he wasn't a complete goalkeeper yet, but even then he had amazing instincts. Nobody would have said he was just a 14-15 year old kid.

JENKIFOCI: What can you say about his attitude, his mentality?

NIKOLIC: He was much more mature than his age. He was respectful and intelligent. He had a great humility about him and you could see that he was trying to learn and improve as much as possible. And he had an incredible confidence. He was just a kid, but he knew exactly what he wanted to achieve in the sport. He was sharp in every single training session, he had a great work ethic.

JENKIFOCI: How common was to have such a young player training with the first team?

NIKOLIC: It was unprecedented. But not only at the Fire, I didn't even experience that at Legia in Poland back in the day. You could be glad if you could bring an 18-19 year old up to the senior team, but to bring a 14-15 years old...it was a miracle! Fortunately, his career was well managed at the club, and he was integrated well into the first team. And when he was ready, he got his chance from the coaching staff.

JENKIFOCI: Do you think Slonina made the right decision by starting his professional career in MLS and not, say, trying his luck with a European club?

NIKOLIC: It was the best possible decision. Getting minutes and match experience is the most important thing for a young player. He got his chance at the Fire at the age of 17. He also knew that if he made a mistake, he wouldn't be out of the team immediately because the coaching staff trusted him. Plus, he knew the league and didn't have to adjust to a new environment, which could be difficult in his first professional years. Moreover, he knew that if he could shine in MLS, he would have the chance to move on to a top European league: like Almirón, or Castellanos, or Jhon Durán did. So I think Gaga also knew that MLS could prepare him for the highest level.

JENKIFOCI: What did you think when you heard that teams like Real Madrid and Chelsea are after him?

NIKOLIC: To be honest, I knew that he will be signed by a top club eventually. Anyone who saw him in training knew exactly what potential he had.

JENKIFOCI: Do you think he made the right decision to sign for Chelsea?

NIKOLIC: You simply can't say no to clubs of this calibre. This is a once in a lifetime opportunity. Slonina is an intelligent guy with the right mentality, so he is aware that now he has to build himself from scratch in London. He has to prove himself in the reserve team first and everything else will come after that. But time is on his side. If he is patient, he will achieve great things. His time will come and I'm rooting for him that when that moment comes, he can make the most of it.

JENKIFOCI: What do you think about his choice of the US national team, despite the fact that the Polish national team also wanted him?

NIKOLIC: I have the privilege of knowing both national teams quite well. The Polish team is an excellent team, but the USMNT has also have a lot of potential. Choosing between national teams is an emotional issue. Gaga was born in America, grew up there and his family lives there, so he probably felt it was the right chocie. But neither choice would have been a bad one.

JENKIFOCI: What future do you see ahead for him in terms of a career in Europe and the US national team?

NIKOLIC: We're talking about a very young player, a lot of unexpected things can happen in a career, so it would be hard to predict. One thing is for sure, he has to make the most of every day, hour, minute and second. But I wouldn't worry about his future, because he's mentally very strong. The next task is the U20 World Cup, where he can show what he can do against the best young players in the world. If he does well in the tournament, he could attract a lot of attention. He has the potential to become the number one goalkeeper for Chelsea's senior team and the USMNT.