Tuanzebe recalls how he was shocked by the pace of Luke Shaw.
"You don't forget the first time you train with the first team," Tuanzebe told Inside United. "It was me, Marcus Rashford and Devonte Redmond, and we went up to training. It was one of the hardest sessions I've had in my life.
"I was in the Under-18s at the time and Paul McGuinness was our manager. We thought we were coming along to watch but we ended up playing in a training game. We were a position team, the first team against us. It was so hard, it was so fast, it was physically on another level.
"I remember vividly that Luke Shaw was absolutely rapid. It shocked me that I couldn't get near him. He was an absolute bullet, just amazing. From that moment, I had him as a benchmark for myself, in terms of how sharp he is. After that session, we had seen what we had to get to. Once we'd had a taste of it, then we all wanted more and more."