Tickets have been in demand for the game between two sides who are separated by five points and a similar number of places in League Two.
Luton remain 6th after losing their game in hand against Wycombe Wanderers on Tuesday night but the Hatters moved quickly after the game to secure their two-goal striker Elliot Lee by extending his loan from West Ham United until the end of the season.
"Elliot's been fantastic for us and we're thrilled to have him for the rest of this season," said boss John Still.
"He's getting fitter all the time and I think that sharpness has been there for all to see in our past two matches."
Facing him in the Northampton attack will be Sheffield United loanee Diego De Girolamo after he made his debut against Bury last weekend.
The 19-year-old has been in action for Italy Under-20's this midweek but will be available for the Hatters match.