Michael Appleton is adamant his players realise they let Pompey down at Coventry.
Now he’s urging them to go towards making amends by putting in a performance against Hull tonight.
The Blues have eight matches to stay in the Championship.
Fratton Park fixtures against Hull and then this weekend against Burnley will be crucial in deciding their destiny.
It’s a survival bid which suffered a massive body blow during a below-par Ricoh Arena display last Saturday.
Appleton joined supporters in being angry at the team’s tremendously disappointing performance during the 2-0 defeat.
Pompey take on Nick Barmby’s Tigers tonight in another one of those must-win occasions.
And he is confident the players are fully aware of what is expected of them.
He said: ‘Yesterday, I told them exactly what I thought. I just won’t accept that.
‘I am not saying it was one of those games where we got battered.
‘We had more of the game and more of the possession and more of the shots if you actually look at the stats.
‘But there just wasn’t that extra yard to go to close someone down, to stop a cross, to stop a shot.
‘There wasn’t that extra couple of yards to make that forward run, to have a gamble, to react to a flick-on or a touch.
‘I am not, for one second, saying Coventry were better than us, because they weren’t, but there was something just not quite there that there’s been for the last six to eight games.
‘Okay, we have lost games during that time, but not in the sort of manner where we got caught short.
‘I have not been able to accuse the players of that since the first day I walked in, against Watford.
‘That’s the first time since I have had to ask questions.
‘They are under no illusions of what I am expecting tonight.
‘After the game on Saturday we could hear the fans still singing and playing the drums when I was addressing the players.
‘It was the realisation they have got to try to perform.
‘You can’t always perform – sometimes you just have a bad game, but you have got to try.
‘They knew they let themselves down and the good thing about football is three days later they get an opportunity to put it right.’
Pompey’s players cannot be accused of a lack of effort since Appleton replaced Steve Cotterill as Blues boss in the middle of November
And he has reiterated the importance of giving their all for the remainder of the season.
He added: ‘I am sure if we play and give it absolutely everything in the next two games – even if results don’t go our way – if the fans see them giving absolutely everything then they will know the players have given it a right go.
‘They don’t mean to play badly on a Saturday. Nobody means to lose a game of football – it just happens on the day.
‘We saw Coventry as an opportunity.
‘And there are probably going to be another two or three more opportunities over the coming weeks because there will be different twists and turns.’