Just run Vierling out there every day. His BABIP and exit velo suggest there's substantial upside.
Castellanos and Realmuto look like they're breaking out of their funk, Bohm has steadily improved, Segura will be back in a couple weeks, Harper in September. So they don't need a lot of offense out of CF.
The bullpen is shining and Brogdon is back and Romero on the way.
Segura is back and Eflin should be in a couple weeks.
So the best move may be no move, or something low key like buying Gallo at a bargain basement cost.