Matt Clarke admitted Pompey are regularly coming up against teams who have the ability to hurt the Blues in League One.
But the former Ipswich man insisted Kenny Jackett’s men can meet the required standards to be successful in the division.
Pompey have made a staggered start in the third tier and are still acclimatising to their new surroundings.
They sit 12th in the table and have suffered back-to-back away defeats to Doncaster and Blackburn in their past two games.
The Blues face another difficult challenge tomorrow when they welcome Bradford to Fratton Park (3pm).
The Bantams are third in the league and reached the play-off final last campaign.
Clarke anticipates another tough afternoon but believes Pompey have the ability to pick up three points.
The centre-back said: ‘There’s a lot of good teams in League One.
‘Last year there were a lot of tricky places to go, but maybe they did not possess the quality.
‘This season we are playing sides who have the quality to hurt you and we have got to respect that.
‘But we have also got to be up to the standard that we can put a show on and beat these sides.’