The game against Paul Cook non-leaguers could potentially allow head coach John Mousinho to reshuffle his pack as he concentrates on maintaining the Blues’ place at the summit of League One.
That’s something the Pompey boss has experimented with in recent games, with match-winner Terry Devlin’s surprise inclusion from the start at Reading last week proving the Blues possess the resources and quality within their ranks to keep opponents guessing.
But with Mousinho insisting he’s taking his very first FA Cup game as a manager seriously, there’ll be no tinkering for the sake of it.
He told The News: ‘We’ll be taking it very seriously and we’ll be strong in terms of the line-up.
‘We’ve had a week leading into this. We don’t have a league game for six days afterwards. I know we’ve got the game on Tuesday night (against Leyton Orient in the EFL Trophy) but we want to take this game in isolation first before we look at anything in terms of team selection for Tuesday.
‘So, yeah, we’ll be approaching it as seriously as we approach a league game.’
Add the fact that Pompey will be looking to avoid the embarrassment of losing to a non-league side live of national television will also be on the Blues boss’ mind heading into the Proact Stadium encounter.
So what can we expect from Mousinho selection-wise ahead of this weekend’s Cup clash with the Spireites?
Well, this is how we think they’ll line up with the added luxury of having nine substitutes on the bench.
5. Centre-back 2: Conor Shaughnessy
The former Burton man has quickly established himself as a key player for Pompey this season. Defensively strong and solid, and a real threat going forward through set-pieces, Mousinho will be hoping that skill set proves advantageous on Sunday. Photo: Jason Brown
6. Left-back: Jack Sparkes
With Connor Ogilvie out with an ankle injury, Sparkes starts - not that the former Exeter man needs an injury to his defensive colleague to get a chance. Those days are already long gone. Photo: Jason Brown
7. Centre midfield: Joe Morrell
Midfield will be a key battle ground on Sunday, with Chesterfield having the likes of former Blues captain Tom Naylor in their ranks. Pompey cannot afford to give their hosts a sniff of a chance here, so battle-hardened Morrell will definitely start. Photo: Jason Brown
8. Centre midfield 2: Alex Robertson
Again, there might be a temptation to throw Ben Stevenson into the starting line-up as Pompey look to contain their hosts. However, Manchester City loanee Robertson has stood up to every tough-looking challenge he's faced with the star and crescent on his shirt. Sunday should be no different. Meanwhile, his ability to brilliantly keep possession of the ball and use it wisely could be key to unlocking the Spireites. Photo: Jason Brown