Evolution as a function of stellar age of the mass (top left panel), radius (top right panel), effective temperature (middle left panel), luminosity (middle right panel), internal structure constant of the star (bottom left panel), and apsidal motion rate of the binary (as computed with Eq. (22) assuming both stars are described with the same model, bottom right panel) for: three GENEC models with an initial mass of 32.8 M_⊙, overshooting parameter 0.20, and Z = 0.015; the single version (blue) and the binary version (green) with initial rotational velocities v_eq,ini = 100 km s⁻¹; and the single version (violet) with zero initial rotational velocity (v_eq,ini = 0 km s⁻¹). Two Clés models with an initial mass of 32.8 M_⊙, α_ov = 0.20, and Z = 0.015, one with no turbulent diffusion (pink) and one with D_T = −2.41 × 10⁷ cm² s⁻¹ (orange), are also presented for comparison. Stellar mass-loss was computed according to the Vink et al. (2001) formalism with ξ = 1 for all models. The observational values of the corresponding parameters and their error bars are represented by the solid red line and the dashed dark red horizontal lines, respectively.