I don't know if Aguero is as important an acquisition as the two fullbacks that this team so desperately needs, as well as a proper LW.
Shoring up those three major areas of concern, combined with a pairing of Quag (Hopefully his pre-injury form, but we won't know that for sure until he goes out there and plays) and Matri, would make more sense to me than returning the both of them, spending all that money on Aguero, and having to go on the cheap for the Fullbacks and a winger.
Please, Juve. Work on those fullbacks. Please. And I don't mean Ziegler, either.