The 19-year-old Germany U21 international went down when chasing Haris Seferovic for the ball in the seventh minute of the game. He was subbed off and immediately sent for examinations at Heidelberg University Orthopaedic Hospital.
“We're all devastated for Niklas,” said director of football at TSG Alexander Rosen following the diagnosis. “He is a great lad who has undergone an incredible development so far. We will support him in every way we can and help see him through his challenging phase in his career.”