The young forward came onto the field as a substitute and scored against Bayern Munich in the Champions League group stages.
Duran has earned the super sub moniker for scoring off the bench multiple times this term.
"He was scouted before I took the job, but once I got on board and I looked at some of his clips, I knew," Ezra Hendrickson, Duran's boss at MLS side Chicago Fire, told BirminghamLive.
"His potential was obvious. He came for first-team football, but sometimes when a teenager comes into a situation and environment like that, it's really hard for them to adapt sometimes. It's a different league, a different culture, he'd never really left Colombia before.
"At times, it was difficult for him. There were people back home he was taking care of, who he had to look out for which was putting pressure on him as a youngster. It took him a while, but you could see in training that potential we all felt he had. Eventually, we knew he'd be our number one.