And it’s a game that promises to stretch Danny Cowley’s options, with the Blues boss keen to give some of his fringe players a chance to shine.
There’ll be a few regulars asked to step up again given the ongoing injury problems the Fratton Park outfit have.
Indeed, the luxury of making the wholesale changes that were evident earlier in the competition are a thing of the past, with the likes of Tomy Lowery, Michael Jacobs and Joe Rafferty out injured, Joe Morrell currently at the World Cup and Joe Pigott ineligible to feature against his parent club.
Cowley still has enough room for manoeuvre – just – as he attempts to keep all members of his squad happy.
But with a real desire to progress in the Trophy, what kind of side can we realistically expect at Portman Road?
Here’s how we think Pompey will line up tonight...
1. Josh Oluwayemi - goalkeeper
The former Spurs youngster will more than likely be given another chance to get some much-needed senior action under his belt again at Portman Road tonight. His penalty heroics in the group stage shoot-out victory against AFC Wimbledon helped the Blues progress - and no doubt he'll be itching to get back out there to show what he's capable of. Photo: Barry Zee
2. Zak Swanson - right-back
Danny Cowley will be wary of asking too much of the former Arsenal defender, given the amount of game time he's had since Joe Rafferty's second operation. Yet Swanson needs games and experience to maintain the consistency he's building in recent weeks. He's becoming an important player for Pompey and that should continue tonight. Photo: Jason Brown
3. Michael Morrison - centre-back 1
It seems the experienced defender has been paying the price for that first-half showing at Charlton last month, with Danny Cowley opting for Sean Raggett and Clark Robertson as his preferred pairing at centre-back since. That means Morrison needs minutes - and that could come against the Tractor Boys tonight as the manager utilises his sqaad. Photo: Jason Brown
4. Kieron Freeman - centre-back 2
The experienced defender is someone good to call on when there's a real need to avoid further injuries to first-team regulars. Will likely be asked to play in an unfamiliar left centre-back role, but Freeman is a reliable performer when asked to step up. Photo: Jason Brown