Pearlitic lamellae in steel are often softened through annealing, a process aimed at transforming them into a more machinable and fabrication-friendly globular microstructure for engineering components. However, our ability to predict and control microstructural evolution during annealing is hindered by a lack of understanding of non-cooperative transformation pathways, especially in bearing steels, where analyzing and comprehending multicomponent diffusion is particularly challenging. In this presentation, I will introduce a highly calibrated, multicomponent, multiphase-field model capable of simulating microstructure evolution and multicomponent diffusion pathways during the thermal treatment of eutectoid steels. Our numerical studies reveal a significant competition between cooperative, non-cooperative, and coarsening regimes during the eutectoid transformation. The simulation results will be analyzed to identify the processing conditions that promote the non-cooperative evolution of pearlite, while also showcasing the phase-field model’s versatility in simulating a range of eutectoid morphologies in steel, including divergent and divorced pearlite.