Victory at Crawley would see Pompey book their spot in the Checkatrade Trophy knockout stages with a group game to spare.
And despite promotion being his priority, Kenny Jackett is targeting a run in the competition for his table-topping team.
There will be changes from the side that lost to Gillingham to suffer a first League One loss of the season on Saturday.
Dion Donohue and Louis Dennis have yet appear this term, but the duo are likely to feature at Broadfield Stadium and Jackett is excited to see them in action.
The Blues boss said: “We had a good start in this competition with a 4-0 victory over Gillingham and if we can get into the latter stages then that would be great.
“The obvious carrot for everyone is a Wembley appearance at the end – if that can be us then it’s fantastic. It’s an incentive for all of us.
“This particular game gives us a chance to use some of the fringe players and, if possible, any promising youngsters who are coming through.
“The vast majority of guys we use will be recognised senior pros, while we need to stick to the rules and regulations.
"This particular game gives us a chance to use some of the fringe players and, if possible, any promising youngsters who are coming through."
“But once we’ve adhered to them – which we always will do – then we want to give some people an opportunity.
“There will be some of our players who will be keen to impress and I’m personally looking forward to seeing them in action.”
Pompey face a fourth tier Crawley outfit that have been beaten just once on their own turf so far this term.
Jackett said: “They will, like us, be highlighting the league, but also looking to do as well as they can in this competition.
“They’re a very good side and will be looking to build on what has been an encouraging home record so far.”
David Wheeler will not be taking part on Tuesday evening after collecting a knock in the latter stages of Saturday’s contest.
Jackett explained: “He’s got an ankle injury after a heavy challenge. It’s a shame because he made a good impression after coming on in the second half.
“I think he’ll miss the game on Saturday as well and then we’ll have to see how quickly he recovers after that.”