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….
9. Harry Jewitt-White
A new breed of talent coming through the academy system. The talented 17-year-old featured twice in this competition last season and will be desperate to make a good impression in a competitive game for Cowley. Photo: JPIMedia
10. George Hirst
The on-loan Leicester striker has made five substitute appearances so far this term, totalling 102 minutes. He'll be itching to start tonight's cup game and out to prove that Pompey do have striking options beyond John Marquis, who has only one goal to his name this season. Tonight offers Hirst a huge window to showcase what he has in his locker. Photo: JPIMedia
11. Ellis Harrison
An 89th-minute substitute appearance against Shrewsbury is all Harrison has to show for his efforts this season to date. Desperately needs game time and desperately needs to show Cowley what he has to offer as the Blues welcomed interest in him during the summer without managing to move him on. Photo: JPIMedia