I'm actually disappointed that we let go of Kagawa. I felt that he would been a better option than Mata, currently, in this 3-5-2 setup as he offers more movement and allow us to play at a faster pace. He would have been the perfect foil for our team at this current moment as Mata's too static and relies more on players creating spaces for him rather than he himself looking for spaces. Plus, Kagawa's creativity could have been unlocked in this role as well. Rooney and van Persie would have revelled playing with him as well with his buzzing movement and constant involvement in the game.
I really am disappointed; I thought he'd be given a chance to clearly compete with Mata, but I think the MK Dons match probably gave Kagawa an indication that he's surplus to requirements. Oh well, it's done, and I'm sure he'd have a great impact at Dortmund and bring the best out of Reus, Immobile, Ramos, Gundogan, and Mkhitaryan.