  We present the systematic analysis of the behavior of elastic pp scattering
cross section in the region of the diffraction peak and the first diffraction
minimum in the framework of quasi-eikonal Gribov-Regge approach, taking into
account the unitarity condition. We use the formalism taking into consideration
the dependence of pomeron signature factor on $t$. We show that although in
this approach one can describe the general features of pp scattering, the
behavior of pp elastic differential cross section in the vicinity of the first
diffraction minimum measured by the TOTEM experiment at LHC can not be
reproduced under any parameter values at standard assumptions of the model.
Physically, in the quasi-eikonal Regge approach the proton proved to be "gray"
and rather large, whereas the TOTEM data indicate that it is smaller and closer
to "black" at LHC energies.
