  We consider the AdS_4 x CP^3 IIA superstring sigma-model in the background of
the "spinning string" classical solution, which possesses two Noether spins. In
the limit when one of the spins is infinite there are massless excitations,
which govern the infrared worldsheet properties of the model. We obtain a
sigma-model of CP^3 with fermions, which describes the dynamics of these
massless modes.
