We discuss the effects of local structure on the electrical transport and magnetic properties of La(0.67)Ca(0.33)Mn(1-x)Ti(x)O(3) system.Based on the intercomparison of the structure, transport and magnetic properties of the Mn site substituted La(0.67)Ca(0.33)MnO(3) with isovalent diamagnetic and paramagnetic ions, we argue that local structural effects have a decisive role to play, compared to the local spin coupling effects, in the ferromagnetic-metallic ground state of the CMR manganites