"Buying English players is a smart idea because we would never have a chance to get Sancho. We are not blind – we saw him, we liked him and then we think: 'Can we get him?' No. Because English clubs don't sell to other English clubs. I don't know exactly what the reason is for that but they don't do it. Now they can go to Germany, which is a wonderful league."
The winger has gone on to flourish in the Bundesliga. The 18-year-old has become a regular at Dortmund and has shone this season with seven goals and nine assists in 22 league outings for the Bundesliga leaders:
Sancho's form has also seen him called up for international duty by England manager Gareth Southgate. The London native made his debut in the Three Lions' 0-0 draw with Croatia in October.
Sancho has talked about why he decided to leave City despite having reached a "verbal agreement" on a new contract with the club, per Liam Corless at the Manchester Evening News:
"Moving away from home was the biggest challenge. Leaving my mum and my sisters behind, I miss them a lot. But I wanted to do what was best for me, and that was what I did.
"It was very tough, especially [missing] my mum. But if you really believe in yourself, you have to do what's best for you. I'm now with my dad in Germany in an apartment.
"Not everyone is comfortable moving from home. If you're ready to play abroad and you believe in yourself, why not?"
The teenager's impressive form in Dortmund has already prompted speculation that Premier League clubs could try to bring him back to the English top flight.
Sancho, who turns 19 next month, is one of Europe's most exciting young talents, and it would be little surprise if some of the Premier League's big clubs were to come calling in the summer.
Dortmund may find it difficult to keep hold of the youngster, but if they do sell they stand to make a huge profit on a player they signed for just £10 million, per BBC Sport.