A short, abrupt increase in energy injection rate into steady rotating turbulent flow is used as a probe for energy currents in the system. The injected excessive energy is localized in time and space and its spectra differ from those of the steady turbulent flow. This allows measuring energy transfer rates, i.e., currents, in three different domains: In real space, the injected energy propagates within the turbulent field, as a wave packet of inertial waves. In the frequency domain, energy is transferred non-locally to the low, quasi-geostrophic modes. In k space, energy cascades locally to small wavenumbers, in a rate that is consistent with 2D turbulence models. Surprisingly however, the inverse cascade of energy is mediated by inertial waves that propagate within the flow with small, but non-vanishing frequency. While supporting some models of rotating turbulence, our observations exclude others, and suggest that in finite systems, inertial waves dynamics plays an important role, even at the vicinity of the 2D manifold.