  We calculate the vacuum average value of the field square and the
stress-energy tensor of a massive scalar field, with non-minimal coupling $\xi$
to the curvature in the short-throat flat-space wormhole background. The
obtained results are not suitable for an analytical analysis and for this
reason we provide a numerical analysis for different values of the coupling
constant, $\xi$. It was shown that the vacuum polarization cannot
self-consistently support the wormhole. Otherwise, the energy-momentum tensor
does not violate the null energy condition near the throat.
