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...
5. Left-back - Charlie Daniels
It's tight for the berth between Daniels and Lee Brown. However, the former is slightly more attack-minded and Kenny Jackett may want that if James Bolton or Jack Whatmough line-up on the opposite side of defence. Photo: Jason Brown
6. Centre-midfield - Tom Naylor
Will continue to operate as the heartbeat of Pompey's team. Photo: Joe Pepler
7. Centre-midfield - Andy Cannon
Made a real difference coming on at half-time at Doncaster. Will surely be restored to the line-up. Photo: PinPeP
8. Centre-midfield - George Byers
The Swanse loanee has made just one start since arriving. However, he can provide Pompey will the sort of passing needed to start creating more chances. Photo: Joe Pepler