The partially-averaged Navier-Stokes (PANS) approach has emerged as a viable scale-resolving bridging method over the last decade. Conventional PANS method, based on the linear eddy viscosity closure, overcomes the scale-resolving inadequacies of Reynolds-averaging but still suffers from limitations arising from linear constitutive modeling of turbulent stresses. Linear PANS has been evaluated in a variety of complex flow-fields including the benchmark case of flow around sphere. In this work, the authors assess the potential of non-linear eddy viscosity closure and further extend the evaluation of non-linear closure in predicting thermal characteristics (besides hydrodynamics) of flow past a sphere. The presented evaluation has been performed on the basis of various surface-related and wake-related quantities. Our results are compared against available experimental and recent direct numerical simulation/ large eddy simulation studies. Our study shows that for the same value of filter-control parameter non-linear PANS performs significantly better than linear PANS.