The absence of Sanchez will likely see Santiago Carreras continue in the flyhalf berth, but coach Michael Cheika has called on Delguy to supply backline cover following the thumping 41-26 loss to the Wallabies in the Rugby Championship.
Argentina have also released prop Mayco Vivas, who recently became a father.
The Pumas led 19-10 at halftime in Mendoza on Saturday, but wilted under enormous pressure from Australia in the second period.