It is a quick turnaround and a long trip for the Cobblers' squad after their 2-1 victory at Notts County on Saturday and against the continuing crisis at Sixfields.
And they come up against a Red Devils side in good form on their home patch with four consecutive home league wins having helped them slowly climb the table after a poor start.
The latest of those came against Bristol Rovers at the weekend when on-loan Oldham Athletic forward Rhys Murphy scored twice within a minute to give the hosts a flying start.
Crawley are using the game to recall their FA Cup victory against Northampton in November 1991, their first ever win in the competition against a League club.