Evolution of half-mass radius r_h of ProCeps (solid lines) and lower mass stars (dotted lines) for clusters of mass M_ecl = 100 M_⊙, 400 M_⊙, 1600 M_⊙ and 6400 M_⊙. The clusters orbit the galaxy at R_g = 8 kpc and have metallicity Z = 0.014. The vertical yellow line shows the time of gas expulsion t_d. The least massive clusters (M_ecl = 100 M_⊙; cyan) mass segregate their ProCeps before t_d, which results in ProCeps being more concentrated than lower mass stars. The following gas expulsion then preferentially unbinds stars from outskirts of the cluster, which are lower mass stars, resulting in a cluster that contains disproportionately more ProCeps. In contrast, the more massive clusters do not mass segregate before t_d, so the stellar loss due to gas expulsion affects ProCeps in a similar way to lower mass stars.