  Aims. We explore the dynamical friction on a test mass in gravitational
systems in the Quasi linear formulation of Modified Newtonian Dynamics
(QuMOND). Methods. Exploiting the quasi linearity of QuMOND we derive a simple
expression for the dynamical friction in akin to its Newtonian counterpart in
the standard Chandrasekhar derivation. Moreover, adopting a mean field approach
based on the Liouville equation we obtain a more rigorous (though in integral
form) dynamical friction formula that can be evaluated numerically for a given
choice of the QuMOND interpolation function. Results. Consistently with
previous work, we observe that dynamical friction is stronger in MOND with
respect to a baryon only Newtonian system with the same mass distribution. This
amounts to a correction of the Coulomb logarithmic factor via extra terms
proportional to the MOND radius of the system. Moreover, with the aid of simple
numerical experiments we confirm our theoretical predictions and those of
previous work on MOND.
