  We calculate the cross section and single-spin azimuthal asymmetry, A_n(t)
for inclusive neutron production in pp collisions at forward rapidities
relative to the polarized proton. Absorptive corrections to the pion pole
generate a relative phase between the spin-flip and non-flip amplitudes, which
leads to an appreciable spin asymmetry. However, the asymmetry observed
recently in the PHENIX experiment at RHIC at very small |t|~0.01GeV^2 cannot be
explained by this mechanism.
