According to the club's website, MacLeod is doubtful with the knee injury that forced him to sit out Tuesday's Ramsdens Cup clash with Queen of the South.
Wallace, meanwhile, did play in the cup tie when he returned to action following a sore hip.
He lasted 85 minutes but will still need to prove his fitness before being named in the starting XI for Station Park.
But three players still absent through injury are Kyle Hutton, Ross Perry, and Chris Hegarty.
Hutton is yet to play this season while Perry and Hegarty have ankle problems.
Forfar is the only team to beat Rangers this season - winning 2-1 in a League Cup tie seven weeks ago.