Mate I loved Kagawa as a player, he had good first season but after SAF left he never lived up to his potential with us and neither with BVB later.
It's a shame, he had such incredible weight of the through ball, good turn on the ball in crowded areas and elite off the ball movement which resulted in many goals back in 1st stint at Dortmund.
fecking Moyes ruined him and many others in just one season... He never got to play #10 and that was a crime but all in all it would be an understatement to say I'd be disappointed if Sancho had similar impact as Kagawa.