  We study the recent star formation histories of ten galaxies in the Fornax A
galaxy group, on the outskirts of the Fornax cluster. The group galaxies are
gas-rich, and their neutral atomic hydrogen (HI) was studied in detail with
observations from the MeerKAT telescope. This allowed them to be classified
into different stages of pre-processing (early, ongoing, advanced). We use
long-slit spectra obtained with the South African Large Telescope (SALT) to
analyse stellar population indicators to constrain quenching timescales and to
compare these to the HI gas content of the galaxies. The H$\alpha$ equivalent
width, EW(H$\alpha$), suggest that the pre-processing stage is closely related
to the recent (< 10 Myr) specific Star Formation Rate (sSFR). The early-stage
galaxy (NGC 1326B) is not yet quenched in its outer parts, while the
ongoing-stage galaxies mostly have a distributed population of very young
stars, though less so in their outer parts. The galaxies in the advanced stage
of pre-processing show very low recent sSFR in the outer parts. Our results
suggest that NGC 1326B, FCC 35 and FCC 46 underwent significantly different
histories from secular evolution during the last Gyr. The fact that most
galaxies are on the secular evolution sequence implies that pre-processing has
a negligible effect on these galaxies compared to secular evolution. We find
EW(H$\alpha$) to be a useful tool for classifying the stage of pre-processing
in group galaxies. The recent sSFR and HI morphology show that galaxies in the
Fornax A vicinity are pre-processing from the outside in.
