We have demonstrated that the polarization of the fullerene shell considerably alters the polarization potential of an atom, stuffed inside a fullerene. This essentially affects the electron elastic scattering phases as well as corresponding cross-sections. We illustrate the general trend by concrete examples of electron scattering by endohedrals of Neon and Argon. To obtain the presented results, we have suggested a simplified approach that permits to incorporate the effect of fullerenes polarizability into the Neon and Argon endohedrals polarization potential. As a result, we obtained numeric results that show strong variations in shape and magnitudes of scattering phases and cross-sections due to effect of fullerene polarization upon the endohedral polarization potential.