Harry Wilson and Rhian Brewster scored for the European champions but goals from Paco Alcacer, Thomas Delaney and Jacob Bruun Larsen were enough for Dortmund to take a deserved 3-2 win at the University of Notre Dame.
Klopp said, "He's an exceptional talent but he's not the only one in England at the moment. That age group has already a few - Rhian Brewster is the same age. [And there is] Raheem Sterling, for example. I don't want to forget any wingers, but there are a lot of talents; young and very, very promising players in England. There is no doubt about the potential of Jadon Sancho.
"His speed and body control at the highest speed is his main strength. Being good in big spaces and in small spaces makes you a pretty interesting player – and that's what Jadon is. Yasser [Larouci] our 18-year-old left-back played against one of the biggest talents in world football and did pretty well the whole night. The pitch helped a little but, but still he did really well."