This article presents the results of a numerical study focused on the investigation of the effects of adjusting the microstructure of the supports and functional layers of solid oxide fuel cells (SOFCs). This concept was developed in order to improve the distribution of fuel in the structure of the electrode and in the reaction zone. The current study includes numerical simulations of the solid oxide cell (SOC) using open-source Computational Fluid Dynamics (CFD) code with an electrochemistry module to define guidelines for possible improvements of performance by tuning the porosity of selected layers of the cell. Based on the experimental data, the porosity of the anode functional layer (AFL) and anodic support layer (ASL) was studied using the Modified Fick Model (MFM), which includes the Knudsen diffusion. In the modeling, the porosity of both layers was considered in the range of 30% to 60%. It was determined that cell performance is sensitive to changes in the microstructure of both parts of the fuel electrode. The proposed approach delivered a qualitative assessment of the potential of fine-tuning microstructure to improve SOC performance. This work presents insight into the physics of the gas diffusivity in the support and anode functional layer. The analysis revealed that appropriate adjustment of the porosity of anode layers has a major impact on SOFC performance.