For Pompey’s opening game in the competition at Crawley, only Ronan Curtis started the league match against Port Vale three days earlier.
And that type of rotation is expected again as Cowley looks to get minutes into the legs of those who have been on the fringes in recent fixtures.
Several of the club’s academy youngsters could also be called upon to make up the numbers.
So who will the manager be turning to for tonight’s fixture?
Here’s how we think the Blues could line up.
. Portsmouth walk out on to the pitch during the EFL Sky Bet League 1 match between Ipswich Town and Portsmouth at Portman Road, Ipswich, England on 1 October 2022.
Danny Cowley is expected to make wholesale changes to his line-up for tonight's Papa John's Trophy game against Aston Villa under-21s Photo: Jason Brown
. Josh Oluwayemi
The former Spurs youngster started the game at Crawley as he got his first taste of Pompey action following his summer move. He continues to play second fiddle to Josh Griffiths but Danny Cowley is keen to see the 'outstanding' form he shows in training on a match day. Tonight he'll be given another chance to prove his quality - only this time in front of the Fratton faithful. Photo: Jason Brown
. Zak Swanson
The former Arsenal youngster is having to bide his time for first-team opportunities having featured just one in the league this season. That's despite Joe Rafferty missing the past three games through injury and left-back Connor Ogilvie coming over to deputise at right-back. Seen as a 'project' by Cowley, it's these types of games which the manager believes will aid Swanson's development and have him pushing for more game time further down the line. Photo: Jason Brown
5. Denver Hume
The left full-back's 45-minute run-out against Crawley in Pompey's last Papa John's Trophy game was considered an important first stepping stone in Hume's road to recovery following a back injury. Yet he's not been involved since, not even in a match-day squad. Danny Cowley has said the former Sunderland man is working very hard behind the scenes to get back into contention and will play 75 minutes at least tonight. Photo: Jason Brown
6. Reeco Hackett
The forward is keen to nail down a starting place, with eight of his 10 appearances so far this season coming from the bench. He's keen to avoid the super-sub tag so will therefore be bang up for the visit of Aston Villa's under-21s. In that respect, all eyes will be on Hackett as Pompey fans continue to make their mind up on the winger. Photo: Malcolm Bryce
7. Ryan Tunnicliffe
The midfielder has found himself back in the fold following his substitute appearance against Ipswich on Saturday - only his second appearance for the Blues in all competitions this season. Those opportunities are expected to continue with Pompey suffering midfield injury problems in recent weeks. It will now be up to Tunnicliffe to seize the unexpected chance he's been given. Photo: Jason Brown
8. Jay Mingi
The youngster is a doubt for tonight's game because of a shin injury. But with opportunities few and far between them so far this season, he will be desperate to get more game time under his belt. Another one to be considered a Pompey 'project' but from what fans have seen of the midfielder so far, they're keen for Mingi to get his Pompey career up and running properly. Photo: Simon Davies