The vast majority of RF coil design techniques are based on reducing the coupling level to increase the coils' power efficiency. The assessment of scattering (S) parameters plays a crucial role in these techniques. However, just by checking S-parameters, we cannot be sure that the coil's accepted power generates a field with useful characteristics. Here, we propose to perform the co-simulation on transmit array coils and replace unknown capacitors with power sources. Extraction of the field profiles of the coil's lumped ports/elements could provide the opportunity to involve the field-dependent parameters in the minimization procedure of finding the coil's capacitors.