Effect of rotation on a 25 M_⊙ evolutionary model. Left: log g−log(T_eff) diagram. Middle: log(N/C)−log(N/O) diagram for models at different velocities. Right: log(N/C)−log(N/O) diagram for a model including magnetic field and V/V_c = 0.6. The bold part of the tracks corresponds to the main sequence. Dots in the middle panel correspond to a surface log g= 3.5, i.e. the minimum value for dwarfs and giants in the lefthand panel; in the righthand panel, log g is always higher than 3.5. Models for V/V_c = 0.4 are from Ekström et al. (2012). Models for higher velocities have been computed for the present study with the Geneva code until the red supergiant phase.