Kenny Jackett has welcomed the opportunity to quickly put defeat to Charlton to bed.
Pompey travel to Walsall on Tuesday night for their latest game in League One - just three days after Saturday's disappointing 2-1 loss at The Valley.
The Blues' ever-fading hopes of making the top two suffered yet another blow with defeat against a promotion rival in south London.
And with momentum needed for what looks increasingly like an extension to their season via the play-offs, the manager has embraced the prospect of getting straight back into action.
Jackett believes the Walsall trip provides a great opportunity for his squad to rectify Saturday's wrongs.
The Saddlers currently sit 16th in the table – three points above the drop zone.
But he concedes the players' approach to proceedings at the Banks's Stadium must be right if they are to reverse form that has seen them record just two league wins since the start of the year.
'The game comes quickly after the Charlton game, which is good,' said Jackett.
'It's a different type of game. Walsall are fighting for their lives down there and they'll be wanting to pick up the points sooner rather than later.
'But, for us, we want to get back to winning ways as soon as we can.
'We're disappointed with the loss on Saturday, we understand this will be a different game, but our attitude, our mentality, has to be right.
'Of course (it's a must win).
'In professional football you always need to win your next game, whether you are at the top or the bottom - you want to be winning your next game.
'I'm pleased after Saturday that there's a game coming quickly for us.
'It's one were we want good momentum going into the end of the season.
'Obviously, we don't want to be playing poorly or inconsistent with our results, we don't want that to be the case.'
Jackett added he took comfort from the way his side attempted to wrestle a point out of the game at Charlton.
'We finished the game strongly on Saturday, which was pleasing.
'We didn't go down without a whimper. We had chances at the end and certainly put pressure on them to get the equaliser.
'So if you have to lose, that's one way.'