That could see the head coach name an entirely different starting XI from the side he named for the 1-0 league defeat at Wigan 10 days ago, with Pompey keen to get match minutes into the legs of their fringe players.
Cowley also wants to give youth a chance, with six or seven of the Blues’ academy youngsters likely to travel to Plough Lane for tonight’s fixture (7.45pm kick-off).
But what can we expect from Pompey tonight in terms of a starting XI?
Well, here’s how we think they could line-up in maybe a 3-5-2 formation….
1. Alex Bass
The 23-year-old has had to take a back seat to Gavin Bazunu after starting Pompey's first two games of the season. He'll be keen to impress on his return and prove to the Cowleys that he's more than capable of becoming the Blues' No1. Photo: JPIMedia
2. Haji Mnoga
Mnoga is currently on loan at non-league Bromley but is eligible to play for Pompey in the EFL Trophy. The defender needs regular football under his belt and, fresh from signing a new three-year-deal at Fratton Park, he'll want to put on a show on his brief return to the Blues set-up. Played 75 minutes of Bromley's 2-2 draw at Chesterfield on Saturday. Photo: JPIMedia
3. Paul Downing
The defender is yet to play this season because of injury. Featured three times under Cowley at the end of last season so will be desperate to kick-start his fresh start under the manager. Photo: JPIMedia
4. Connor Ogilvie
Former Gillingham man has had a stop-start to his Pompey career to date, playing various positions since his summer arrival. Will be keen to nail down a regular starting spot. Photo: JPIMedia