The Championship side astonishingly threw away a three-goal lead to draw 3-3 with Plymouth Argyle at the weekend, a game that saw Robbie Brady substituted with an ankle injury in the first half.
The Republic of Ireland international will not be available for the visit of the Gunners, and the same goes for Ched Evans (discomfort), Patrick Bauer (elbow) and Will Keane (tendon), as well as suspended striker Milutin Osmajic.
The absence of Brady should not cause Preston to press the panic button, though, as his replacement on Saturday - Brad Potts - found the back of the net and should be a straight swap on the left-hand side.
Potts could comprise part of a five-man backline protecting goalkeeper Freddie Woodman, as Liam Lindsay, Andrew Hughes, Jordan Storey and Aston Villa loanee Kaine Kesler-Hayden also endeavour to keep the Gunners at bay.
Ben Whiteman and Mads Frokjaer-Jensen should both hold their places in the engine room as well, but the fresh legs of Ryan Ledson - who captained Preston to an unbelievable 16-15 shootout win over Fulham in round three - could now be preferred to Ali McCann.
As Osmajic serves his lengthy ban for biting Blackburn Rovers' Owen Beck, Emil Riis and Sam Greenwood - a former Arsenal youth product - should form the hosts' two-man strikeforce.
Preston North End possible starting lineup:
Woodman; Kesler-Hayden, Hughes, Lindsay, Storey, Potts; Whiteman, Frokjaer-Jensen, Ledson; Greenwood, Riis