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….
5. Mahlon Romeo
The transfer deadline day signing from Millwall will be given the chance to shine as he's handed his debut. There's a lot of excitement about his arrival and what he can bring to the team down the right. All eyes will be on him tonight. Photo: JPIMedia
6. Louis Thompson
The midfielder has had to bide his time for his Pompey debut. Danny Cowley always said it would take a while for Thompson to be involved - now the former Norwich man has his chance. Has undoubted quality but needs to stay fit to build momentum. Photo: JPIMedia
7. Michael Jacobs
Jacobs has only amassed 68 minutes of football so far this season so desperately needs game time. Is also yet to start a match this season after his well-publicised failed moved to Ipswich. Cowley is a big fan but just hasn't utilised him much so far. Has a big chance to make an impression tonight. Photo: JPIMedia
8. Gassan Ahadme
The on-loan Norwich attacker is yet to get off the mark this season despite a hugely-impressive pre-season, when he was banging goals in for fun. Tonight could be a chance to rediscover his form in front of goal and some confidence. Photo: JPIMedia