Andy Awford believes his side need to display their mettle and deliver a performance of character to put promotion-chasing Southend United to the sword.
The Blues are looking for their first win in two months at Fratton Park against the Shrimpers – with no victories in their past seven games.
The tension created by that run was evident in last weekend’s 1-1 draw with Burton.
After Jed Wallace opened the scoring, Pompey found themselves dropping deeper as the game wore on against the Brewers – before the visitors found an equaliser.
Awford feels his players have to show their resolve if and when the tension and pressure mounts tomorrow.
He said: ‘Bravery comes in many shapes and forms, that’s what Alan Ball said.
‘It’s not just about smashing into tackles. It’s about getting on the ball at the right times and it’s about getting together as a unit and staying up the pitch.
‘It’s about getting on the ball and doing it right. You’ve just given three passes away. Will you go for that pass again for the fourth? That’s bravery.
‘You do end up dropping five yards deeper. It’s natural. I don’t care who you are.
‘Chelsea will do it. Every team will do it. It’s a human nature thing.
‘I have done it on many occasions as a player. Sometimes you concede and others you will sit back, counter and score another one. It happens.
‘But I do believe the more times you do the right things the more opportunities you will get to win games.
‘That’s what we have to keep believing. It’s a test for the players but that’s what they have to do.
‘If that ball goes astray in the last 10 minutes it can get edgy. I’ve got no problem whatsoever with that.
‘If you can’t live with that don’t come here to play.
‘That’s how it is. I’m no different stood on the sideline. That’s how we are as people.
‘Bravery is a massive word. The two words I use are bravery and desire. They are the words for me.
‘That came from Alan Ball. He said bravery came in many shapes and forms.’
Despite Pompey’s drop in form, Awford dismissed any notion his players are not showing desire.
But the disappointing 2-0 loss to Southend at Roots Hall in September was an occasion he felt his team were wanting for effort. That will be a motivation tomorrow.
Awford said: ‘I wouldn’t question the players’ desire.
‘That’s where I lose the plot when they are not at the right levels.
‘But our work ethic has been okay. I don’t think that has been a problem.
‘My teams generally have a go and that rarely doesn’t happen, but it did at Southend
‘I was angry because I don’t accept that.
‘If it’s a misplaced pass I accept that, but there’s no excuse for a lack of effort.’