  A Generalized Langevin Equation with exponential memory is proposed for the
dynamics of a massive intruder in a dense granular fluid. The model reproduces
numerical correlation and response functions, violating the equilibrium
Fluctuation Dissipation relations. The source of memory is identified in the
coupling of the tracer velocity $V$ with a spontaneous local velocity field $U$
in the surrounding fluid. Such identification allows us to measure the
intruder's fluctuating entropy production as a function of $V$ and $U$,
obtaining a neat verification of the Fluctuation Relation.
