Lee Brown stressed Pompey must show ‘character and courage’ after conceding Fratton Park will be on a knife edge tonight.
The Blues host Lincoln in League One following a miserable 1-0 defeat to AFC Wimbledon on Saturday.
The loss – Pompey’s fourth of their third-tier campaign – leaves them languishing 18th in the table and just one point above the relegation zone.
Pressure has cranked up on under-fire boss Kenny Jackett, while supporters have grown apathetic with the current situation, demanding things significantly improve.
For those reasons, Brown’s expecting the atmosphere at PO4 to be tense from kick-off against the Imps.
But the vice-skipper insisted he and his team-mates must display the character to overcome it and deliver three points.
Brown said: ‘The fans will back us but it will be on a knife edge, and rightly so.
‘It's going to be on a knife edge. As players, we have got to expect that and we've got to show some character and courage to play through it if the atmosphere does go like that.
‘Hopefully we score early and everyone will be jumping up and down.
‘We're going to need men and going to need characters who, either way, don't really care if it goes like that.
‘No disrespect, but you have got to show some resilience and some steel.
‘If it does, you've got to stay strong or you just go under and you can't let that happen because this club is too big to let that happen.’
Brown admitted the reverse at Kingsmeadow put a dampener on the rest of his weekend.
But he knows spirits can improve by defeating Michael Appleton’s Lincoln.
The left-back added: ‘After every game, there's a massive debrief as players and we try to think where it has gone wrong.
‘We don't just go home and forget about it. It ruins people's weekend - it ruined my weekend.
‘You don't just think "it's done now" it ruined my whole Sunday and Monday but luckily we have a game to put things right.’