Port Vale can take a huge step towards promotion by winning their home fixture against struggling Aldershot while Burton Albion can leapfrog the Cobblers if they recover from a thrashing at Vale Park and beat Wycombe Wanderers.
"I always thought our two home games coming up against Wycombe and Plymouth would define our season more than this game," said boss Gary Rowett after the 7-1 reverse on Friday night.
Rotherham and Exeter also remain in the automatic promotion hunt and they meet at the New York Stadium with both teams looking to arrest alarming slumps in form.
However results go on Tuesday night will not alter the fact that automatic promotion is in Northampton's own hands, starting with Saturday's home game against York City for which chairman David Cardoza is calling on Cobblers' supporters to pack out Sixfields after a turnaround in fortunes under Aidy Boothroyd which he described as 'phenomenal'.