we outline below might not apply to merging clusters in the early stage of a merger, or it may give underestimates of the cosmic ray production of gamma-rays. In general, inverse Compton emission from primary electrons is expected to dominate close to acceleration sites such as large scale shocks [@Miniati2002]. Nevertheless, simulations indicate that the inverse Compton emission from electrons is systematically subdominant at energies relevant to the Fermi telescope compared to gamma-rays produced from pion decays [@pfrommer2004; @pfrommer2007; @nagaiando].

In this work, we consider only the typically dominant gamma-ray emission from pion decays. The inclusion of gamma rays from primary electrons inverse Compton scattering could affect the results of the analysis we present in the following ways. First, the total gamma-ray flux, when considering this additional source, will generically be enhanced, potentially resulting in even better prospects for the detection of galaxy clusters at gamma-ray energies with Fermi-LAT. Furthermore, if IC from primary electrons plays a significant role, the morphology of the gamma-ray emission region from cosmic rays would also be affected, leading likely to a wider extent of the emitting region (including for instance peripheral cluster shock regions). This could, however, potentially hinder the discrimination of a cosmic-ray 