From the looks of it, granny Chiyo's Kinjutsu may come into play. The life transference she did on Sakura. But it's just another speculation.
How could Sakura study that jutsu in Konoha? She would have to do it in the sand village, it is a puppet jutsu from Suna after all. I also think Chiyo invented it? Was that ever cleared up? If she doesn't have any scrolls or guidance to go by, I don't see how this is possible. Or maybe she did contact Suna to research the technique, and if Gaara knows this he will probably take Naruto to her.










