That's the first I've heard about Kurzawa
Defensively I think we need two more class centre backs and for me Hummels & Godin are the players for that role. Them two along with Rojo would be class! Now we have Carrick back I think we'll be ok in defensive midfield.
I'm not a fan of Godin. He's 31 and a bit gaffe-prone, IMHO. Still, he is the heady veteran who could come in, command respect and organize your backline. Hummels would be fantastic, but I would avoid his partner Subotic. Carrick is a good holding player, but you should get another. Strootman would work, but I can't believe the price tag for him. There have been persistent rumors about ex-City destroyer Nigel de Jong. I would truly hate to see him in a United kit, but LvG likes him, and he's a phenomenal wrecker and ball winner. Alex Song, on loan at WHU from Barca, might be a very nice fit, or maybe Ch. Tiote? Song has the ability to create (terrific long passer) and orchestrate in the midfield.