Currently it has been said to be Aru. But Landa is showing form so Astana might consider bringing him in July instead of Aru. Plus you still have Jakob Fuglsang who is a tested domestique and is showing form.
Then you have the support of Westra, Scarponi and Grivko.
Froome has Porte, Roche, Nieve, Thomas and Poels
Contador has Majka, Kiserlovski, Rogers and Paulinho
Quintana has Valverde, Izaguirre, Inxausti and Herrada
Dark horse will the AG2r who will come to the tour with Peraud, Bardet, Vuillermoz and possible Pozzovivo
Then you have the support of Westra, Scarponi and Grivko.
Froome has Porte, Roche, Nieve, Thomas and Poels
Contador has Majka, Kiserlovski, Rogers and Paulinho
Quintana has Valverde, Izaguirre, Inxausti and Herrada
Dark horse will the AG2r who will come to the tour with Peraud, Bardet, Vuillermoz and possible Pozzovivo