Top: As in the upper panel of Fig. 2, but for simulation S4 in which we introduce a putative gap in the gas disk before inserting a subthermal-mass planet. The planet is introduced and evolved inside the dusty ring occurring at the outer edge of the putative gap. Bottom: Radial profile of the pressure support parameter η= −1/2(H/r)² ∂ log P/∂ log r (e.g. Nakagawa et al. 1986; Bitsch et al. 2018) which delimits regions of sub- and super-Keplerian rotation.