Stuart McCall is adamant Scunthorpe can condemn Pompey to their first away defeat of the season.
The Iron boss reckons the Blues are ‘there to be hit at’ – and has told his troops to take their goalscoring opportunities when they arise.
Kenny Jackett's League One table-toppers have been in superb form on the road this term.
They’ve registered seven victories and two draws, a key factor behind their title push so far.
In contrast, Scunthorpe have struggled after reaching the play-off semi-finals last term.
They sit in 15th place, although they have won two of their past three games.
McCall knows his side are the underdogs for the Glanford Park clash.
But the manager is confident the Iron can hand Pompey a maiden loss on their travels.
He told Scunthorpe’s website: ‘Not many people outside our dressing room and the fans will think we can get anything because their away record is really strong.
‘I’m sure they’ll bring a big support and the atmosphere will be good.
‘They’re there to be hit at and that’s what we’ll go out to try to do.
‘There’s growing belief and confidence in the group of players and the staff.
‘There’s positivity about the group and we’re really looking forward to Saturday.
‘It’ll be a tough test but we’re confident we can create against any side and hopefully take the chances that arise.
‘We won at Bristol Rovers last weekend and defeated Burton here last time and came back from three down in the one before (against Oxford).
‘We take a lot from those and just have to keep growing.’