"That's... I don't know..." Joining Watford at the age of seven he later moved to Manchester City and eventually landed in Bundesliga with Borussia Dortmund, becoming the first Englishman to play a Bundesliga match for Dortmund.
"It's completely different now, there are a lot of young players in that group".
England face the prospect of competing in two Uefa Nations League matches against World Cup finalists Croatia and 2010 World Cup champions Spain which, should he feature, would see Sancho have a tough introduction on the global stage.
Sancho, who was one of the standout figures in the England side that won the U17 World Cup in India, admits it was a wrench leaving England to join Dortmund when he realised he would struggle for game time under Pep Guardiola.
Phil Foden, 18, is yet to become a Manchester City regular but tonight will play for England Under-21s, whose boss Aidy Boothroyd said: 'Phil is at a great club with a great coach and surrounded by great team-mates.
"You just want to go out there and do your best and I'm sure everyone will. Obviously I have got to say thank you to the (Dortmund) manager (Lucien Favre) for playing me, trusting and believing in me", he added.
"It would be a dream come true (to make my debut against Croatia)".
That saw plenty of players with lower league experience included in the squad, such was their necessary path to the top given the relative lack of opportunity in Premier League first elevens for the best of English talent. By doing that he has also sent out a wider message, namely he is watching all English players, including those who are overseas.
Sancho said: "I don't really see myself as a talented player". It's alright. It's a bit hard, but I have the basic words.
But the hosts won't be able to count on any support in their first home match since the World Cup with the game being played behind closed doors in Rijeka.
"Obviously there are a lot of young players in the squad looking to get their chance and keeping everyone on their toes".
"But that won't faze me at all". I think in the long run, this is only going to benefit the England national team.
Tottenham, in particular, are keen on signing the 18-year-old wunderkind, who is believed to be valued around £100 million.