The assembly of clusters of galaxies through mergers events and constant accretion of material from the cosmic web is key to further understanding the evolution of large scale structures in our Universe. The internal dynamics of their hot gaseous atmosphere, its interaction with their galaxies and their hosted super massive black holes bear the signatures of this assembly process. Being able to probe the internal dynamics of this intra-cluster gas through the characterization of their velocity structure is thus crucial to that end. An accurate mapping of turbulence and bulk motion in galaxy clusters, relying on the use of diagnostics such as the line shifts, line broadening and structure functions, requires X-ray spectroscopy data with high enough spectral and spatial resolution. Such capabilities will be provided by the Athena/X-IFU instrument, scheduled for launch in the early 2030’s, through its array of TES (Transition Edge Sensor) microcalorimeters. Those superconducting devices will deliver X-ray data in the soft energy band with an unprecedented energy resolution of less than 2.5 eV at 7 keV. In this work, we investigate the ability of the X-IFU to probe the hot gas and provide constraints on the turbulent cascade of the intra-cluster medium. After a short presentation of the TES principle, I’ll show by the mean of mock simulations that the X-IFU instrument will allow us to recover such information, and discuss the optimization of the strategy for future observations toward that end.