After suffering a 2-1 loss at Doncaster on Tuesday, the boss needs to find a way of remedying the Blues’ faltering League One promotion bid.
A top-two finish is looking more and more unlikely, with Pompey now facing a battle to cement a play-off spot.
Jackett's side not only need to deliver three points against the relegation-threatened Cobblers but deliver a performance that can prove the fillip for a big push in the business end of the season.
The Pompey manager will surely make changes from the loss to Donny, with teenager Haji Mnoga likely to be taken out of the side.
The Blues are hopeful James Bolton will be back fit while Michael Jacobs is also back in training.
Here’s how we think the visitors will line-up at Sixfields...
1. Goalkeeper - Craig MacGillivray
The Scot might have been a tad disappointed he was beaten at his near post for Doncaster's second goal but he's been in top form throughout the season. Photo: Daniel Chesterton
2. Right-back - Jack Whatmough
The fans' favourite gave a decent accout of himself when switched to a makeshift role at Doncaster. Will offer plenty of solidity. Photo: Jason Brown
3. Centre-back - Sean Raggett
Been ever-present this season and there's little reason why he will lose his spot. Photo: Joe Pepler
4. Centre-back - Rasmus Nicolaisen
The Dane is enjoying his best spell in Pompey's side and his distribution has been impressive at times. Photo: Joe Pepler