“I always wanted to play in Europe. “Going to Dortmund was definitely a perfect first step for me. It was awesome, and I learned so much. I grew up there – I went over there when I was 15.
“Now, to be here and come to the Premier League when I was 20, I think it all worked out very well so I’m really happy with the path.
“I was confident and felt like I had a good couple of years in the Bundesliga, and obviously with the opportunity to come to a club like Chelsea – it was just something I couldn’t turn down.
“I just felt like the timing was perfect and I’m really happy that I made that choice.”