The midfield could see things freshened up, while Cowley could also be tempted to play around with his defence.
Here’s how we think the Blues could line up tomorrow against the U’s, with four changes made to the side that lost 1-0 at MK Dons.
1. Goalkeeper - Gavin Bazunu
The Republic of Ireland keeper can do no wrong at the moment and every game he plays showcases what a coup Danny Cowley pulled off to get him to Fratton Park on loan. Photo: JPiMedia
2. Right-back - Mahlon Romeo
The on-loan Millwall wing-back replaced Kieron Freeman in the second half at MK Dons last time out as Danny Cowley went in search for greater attacking potency down the right. Freeman is no slouch when it comes to getting forward, but it appears Romeo might just have the edge in that department - and that could be crucial tomorrow against a U's side who will be desperate to protect their goal. Photo: JPIMedia
3. Centre-back - Sean Raggett
The defender is currently a 7+ out of 10 every time he sets foot on the pitch this season. And that's vital as long as Pompey's struggles up front continue. Photo: JPIMedia
4. Centre-back - Clark Robertson
Like Raggett, Robertson has been immense this season, justifying why Danny Cowley swooped for him in the summer. If he stays clear of injury, the centre-back could end up being the Blues' most important signing of the season. Photo: JPIMedia