  We demonstrate how potential impurities are a very powerful tool for
determining the pairing symmetry in graphene proximity-coupled to a
spin-singlet superconductor. All d-wave states are characterized by subgap
resonances, with spatial patterns clearly distinguishing between nodal and
chiral d-wave symmetry, while s-wave states have no subgap resonances. We also
find strong supergap impurity resonances associated with the normal state Dirac
point. Sub- and supergap resonances only interact at very low doping levels,
then causing suppression of the supergap resonances.
