Maitland-Niles is an option at defensive midfield don't forget. Zelalem should really be playing in this as well, unless we've lined him up another loan.
I can see Wenger paying lip service to the Fa Cup this season, perhaps due to the most serious threat he's ever faced in losing his super duper top 4 consistency record.
A similar level team to Forest away in the League Cup, or possibly weaker with the injuries.
Missing/rested: Sanchez, Ozil, Walcott, Perez, Coquelin, Cazorla, Elneny, Gibbs, Debuchy, Koscielny