Understanding and modelling turbulent transport in thermonuclear fusion plasmas is crucial for designing and optimizing the operational scenarios of future fusion reactors. In this context, plasmas exhibiting state transitions, such as the formation of an Internal Transport Barrier (ITB), are particularly interesting since they can shine light on transport physics and offer the opportunity to test different turbulence suppression models. In this paper we focus on the modelling of ITB formation in the Joint European Torus (JET) [1] hybrid-scenario plasmas, where, due to the monotonic safety factor profile, magnetic shear stabilization cannot be invoked to explain the transition. The turbulence suppression mechanism investigated here relay on the increase of the plasma pressure gradient in the presence of a minority of energetic ions. Micro-stability analysis of the Ion Temperature Gradient driven modes (ITG) in the presence of a fast-hydrogen minority show that energetic ions accelerated by the Ion Cyclotron Resonance Heating (ICRH) system (hydrogen, nH,fast/nD,thermal up to 10%, TH,fast/TD,thermal up to 30) can increase the pressure-gradient enough to stabilise the ITG modes driven by the gradient of the thermal ions (deuterium). Numerical analysis shows that, by increasing the temperature of the energetic ions, electrostatic ITG modes are gradually replaced by nearly-electrostatic modes with tearing parity at progressively longer wavelengths. The growth rate of the micro tearing modes is found to be lower than that of the ITG modes and comparable to the local E×B-velocity shearing-rate. The above mechanism is proposed as a possible trigger for the formation of internal transport barriers in this type of discharges.