  I study the effect of scalar and spin-orbit absorption potentials, in the
production of a nonzero Sivers-like asymmetry in hadron-hadron high energy
collisions (Drell-Yan and single spin asymmetries). A basic model is built for
the intrinsic state of a quark in the projectile hadron. S-wave and P-wave
2-component states are considered. Before the hard event, this quark is subject
to absorbing scalar and spin-orbit local mean fields simulating interactions
with a composite target. The relevant interaction terms are found to be the
imaginary diagonal spin-orbit ones. Spin rotating terms, and scalar absorption,
are not decisive. For $x$ $=$ 0 the found Sivers asymmetry vanishes, while at
larger $x$ its qualitative dependence on $x$, $K_T$ follows the usual trends
met in available models and parameterizations. Given the present-day knowledge
of the considered phenomenological interactions, it is not possible to
establish whether the related Sivers-like asymmetry is a leading twist one.
