The role of local particle injections and accelerations in determining the radial profiles of fluxes of trapped magnetospheric particles is assessed. A simple, one-dimensional, steady state model of radial transport in which diffusion is balanced against source-sinks is adopted and solutions in two cases are contrasted. The first case is that of point injection near the magnetospheric boundary followed by loss- and source-free, &mgr;- and J-conserving radial diffusion. In the second case, injection is going on over a band of radii in addition to radial diffusion, and the observation point is immersed in this injection region. In the case of point injection the observed spectrum is the injection spectrum suitably scaled in energy; in the case of banded injection, radial mixing results in a spectrum whose energy structure is determined by the radial dependencies of the diffusion coefficient, the injection, and the background magnetic field in addition to the input spectrum itself. The relevance to contemporary Jovian and terrestrial observations is pointed out.