Christian Burgess has refused to rule out Pompey clinching automatic promotion this season.
The Blues were condemned to a 2-1 defeat at Charlton on Saturday, leaving them eight points off the top-two places in League One with just 10 games to go this season.
But centre-back Burgess insists the belief still remains within the squad of finishing in one of the two automatic promotion spots this term.
Pompey know there is very little room for error in the final run-in if they are to finish above Luton or Barnsley.
Yet Burgess does not feel the current top two will take maximum points from their final 10 matches, which could hand fourth-placed Blues a chance of reaching the Championship without having to face the play-offs should they capitalise.
He said: ‘There’s still a big opportunity with 30 points to play for.
‘I don’t think they (Luton and Barnsley) are going to go and win all of their games so we’ve just got to take every game as it comes.
‘There’s plenty of belief and some really good players in our dressing room – it’s by no means over.
‘I don’t think you can write us off at all for that automatic promotion spot still.
‘It’s a big thing to play to go up to the Championship and there should be good sides in there, which I think there are battling it out for the right to go up.
‘It should be entertaining whatever the finish is to the season.’
Pompey’s defeat at the Addicks was a first in the league since January, although Jackett’s men have won just one of their previous seven outings in the competition.