Pompey welcome Scunthorpe to Fratton Park on Saturday aiming to achieve something they have yet to do all season.
The Blues play host to the Iron with both clubs currently in the League One play-off positions.
Kenny Jackett’s side sit sixth, with Scunthorpe occupying fourth spot in the league table.
But Pompey’s position in the standings has been achieved without them beating any of the teams presently in the promotion and play-off positions.
In fact, all they have to show for their efforts to date is one point from a possible 15.
That solitary registration came courtesy of a 1-1 draw at league leaders Wigan.
But even that could have been a heavy loss if it wasn’t for a string of top-class saves from goalkeeper Luke McGee.
In head-to-head meetings with those currently above them in the standings, the Blues have suffered losses on the road to Blackburn, Shrewsbury and Scunthorpe.
They also registered a home defeat at the hands of Bradford – although Pompey can rue a number of missed chances that day.
It’s a worrying trend going into Saturday’s crucial clash, with the Blues looking over their shoulder at the teams in hot pursuit.
But the Iron’s form against the top six isn’t something they can exactly rave about, either.
Apart from their comprehensive 2-0 success over Pompey at Glanford Park in September, they have only won at Bradford – and the Bantams’ form at Valley Parade sees them placed 14th in the League One home form table.
Jackett’s troops, meanwhile, have made Fratton Park a fortress again.
Following a period of fluctuating results at the start of the campaign, the Blues’ recent form on their own patch has been the fulcrum behind them moving into the play-off places.
Pompey have won their past five league matches at Fratton Park and boast the joint-second best home record in League One.
In total, they’ve picked up 28 points - the same amount as Wigan, with Shrewsbury (31) only returning more.
However, Scunthorpe’s overall form on the road is something they will take heart from in the build-up to their south coast visit.
The Iron have the fourth-best record away from home in League One, having collected 24 points.
Their three defeats on the road have come against title-chasing Shrewsbury, promotion-hopefuls Blackburn and a surprise defeat at struggling Walsall.