Just 17, Karl is fast emerging as arguably the best talent seen in Germany for a decade.
England captain Kane told Bundesliga media: "Lenny has been fantastic so far. He has extraordinary qualities, especially in tight spaces, and his contribution is crucial for us.
"We often find ourselves facing very deep defenses or systems like 5-4-1, where teams close together, making it difficult to find openings. Lenny, thanks to his speed and ability to beat his man, is able to open up those spaces. In this respect, he's very reminiscent of Jamal Musiala: his ability to create numerical superiority allows him and his teammates to get to the shot more easily."
Kane also said: "He works hard for the team. With our training method and such a demanding coach, it couldn't be otherwise. He's a quiet boy, as is only natural for a 17-year-old in such an environment, but he's learning every day and enjoying his experience in the group. His presence has really made the difference in many matches this year."