Evolution of the stellar rotation during the first part of the MS for the three models with 9 M_⊙ and Z = 0.002 with the same value of J_tot, but with different rotation profiles on the ZAMS, as described in the text. Upper panel: equatorial rotational velocity as a function of the central mass fraction of hydrogen H_c. The internal rotation profiles on the ZAMS (H_c ≃ 0.744) and at H_c = 0.73 are superimposed. Lower panel: ratio of the surface angular velocity to the critical angular velocity as a function of the central mass fraction of hydrogen. In both panels, the two stages of the rotation profiles are indicated by vertical dotted lines.