The Cobblers, rooted to the bottom of the Football League, sacked Aidy Boothroyd on Saturday and face a trip to Burton Albion on Boxing Day as they begin to move on
The former Watford and Coventry City boss was relieved of his duties on Saturday following a 4-1 home defeat to Wycombe Wanderers that left them three points adrift of 22nd-placed Torquay United.
And Northampton could have wished for a kinder Boxing Day clash as they head to the Pirelli Stadium to face a Burton side, who sit fifth and are on a five-match unbeaten league run.
Fellow relegation-zone-dwellers Bury face a similarly tough game as third-placed Scunthorpe United, who have won four of their last five fixtures, head to Gigg Lane.
At the top end of League Two, leaders Chesterfield have suffered defeat just once in their last nine league outings and will be hoping to keep their noses ahead of second-placed Oxford United when they host Hartlepool United.
Oxford will want to extend their own unbeaten record to six in the league against Plymouth Argyle, who ended a three-match winless league run with a 2-1 victory over Bury at the weekend.
Morecambe have the chance to pull themselves level on points with fourth-placed Fleetwood Town as Graham Alexander's men travel to the Globe Arena for a local derby, while Newport County and Southend United could strengthen their grip on a play-off spot with maximum points at Wycombe and AFC Wimbledon, respectively.
Rochdale, meanwhile, are aiming to climb into the top seven and they welcome struggling Mansfield - without a win in 12 league matches since the end of September - to Spotland.
Elsewhere, Portsmouth are hoping to bring an end to their nine-match winless streak in all competitions against Dagenham and Redbrdge, who are following up from back-to-back defeats, and Accrington Stanley face struggling York City at the Crown Ground.
The day's remaining two fixtures feature a pair of South West derbies, with Torquay looking to leapfrog local rivals Bristol Rovers at Plainmoor and Exeter City hoping to do the same to Cheltenham Town at Whaddon Road.