The dynamical features of a Gay-Berne mesogen have been investigated through an analysis of molecular dynamics simulation data. The cage potential confining instantaneously the orientational motion of the molecules, for both the isotropic and nematic phases have been defined and parameterised. Tbe statistical analysis of the data obtained from the MD simulations show that no significant differences exist in the local structural and dynamical properties of the cage in the isotropic and nematic phases, but that a clear dependence of the cage potential does exist with respect to its orientation in the nematic phase.