Wallach (concussion) will play the second game of his rehab assignment Tuesday with High-A Jupiter.
Wallach went 0-for-2 in his first rehab contest Saturday. A concussion has kept him out of action since late May. Bryan Holaday has hit .311/.404/.489 in 16 games as the Marlins' backup this season and could keep Wallach from reclaiming his spot once healthy.