Firpo missed the first six games of the current league season owing to a knee injury suffered in the Whites’ first pre-season fixture.
The 26-year-old, who was signed from Barcelona, returned to action for the last half hour of the draw at home to Aston Villa, but had to be left out again.
Marsch confirmed that the defender picked up a little something after the stalemate at Elland Road against Villa and was given the week off to recuperate.
Pascal Struijk has done well as a makeshift left-back so far, including scoring the only Leeds goal in the defeat to the Eagles.
The Whites welcome league leaders Arsenal to Elland Road next Sunday after their winless run extended to five games.
“Junior Firpo just picked up a little something after the last game so we wanted to give him the week and he’ll be ready by next week”, Marsch told his post match press conference.
Leeds are currently in 14th place in the Premier League table after eight games following the loss at Selhurst Park at the weekend.
