Victory against the Bluebirds - one of the Blues’ main relegation rivals - will set the tone for a crunch set of fixtures that immediately lie in wait and could determine the club’s Championship fate.
Anything other than that at P04 - a place where John Mousinho’s side have enjoy plenty of success in recent months until Millwall’s visit two weeks ago - will pile the pressure on Pompey and give those around them in the lower reaches of the division hope that they can overcome their own relegation struggles.
The team Mousinho puts out against 19th-placed Cardiff will be imperative. Last Saturday’s trip to Sheffield United saw the head coach name an unchanged side to the one that drew 0-0 with Burnley. That surprised many of the Fratton faithful. So the questions is: will he do the same tonight after the Blues produced their best performance of the season at Bramall Lane - despite the defeat? Or will he make changes to his side in areas that could possibly need fresh legs?
Here’s how we think Pompey could line up against Cardiff, with a key decision taken on one of the Blues’ six loan options - Isaac Hayden.
1. Pompey entertain Cardiff City at Fratton Park in what is a huge game at the bottom of the Championship
Pompey entertain Cardiff City at Fratton Park in what is a huge game at the bottom of the Championship | National World
2. Goalkeeper - Nicolas Schmid
The Austrian couldn't be faulted for either of Sheffield United's goals on Saturday. He remains Pompey's No1 - and rightly so! | National World
3. Right-back - Zak Swanson
Swanson gets the nod over Terry Devlin in the continued absence of Jordan Williams. Did well in a superb team performance against the Blades but was caught upfield for United's opening goal on Saturday. | National World
4. Centre-back 1 - Conor Shaughnessy
Pompey look a far better side with Shaughnessy restored to the back line. Oh, how the Blues have missed him. The Irishman was substituted in the second half against Sheffield United purely as a precation as the Blues manage his game time after more than five months out. He'll start against the Bluebirds. | National World