  We extend the polaron variational treatment previously developed for the
propagator to the case where one nucleon and $n$ external mesons are present.
Using the particle representation of the scalar Wick-Cutkosky model this is
done in lowest order of an expansion of the exact action around a retarded
quadratic trial action. In particular, we evaluate the form factor for
scattering of mesons from the scalar nucleon and determine the radius of the
dressed particle. After analytic continuation to Minkowski space we study
elastic meson-nucleon scattering both analytically and numerically near
threshold and show that it is essential to incorporate the correct behaviour of
the retardation function at large proper times. Only if this is done the
optical theorem is approximately fulfilled over a range of energies and
coupling constants.
