Pompey will remain out of the play-off places - even if they overcome Blackburn Rovers at Fratton Park tonight.
Kenny Jackett's side sit eighth in the League One table on 46 points.
They can overtake sixth-placed Bradford (49 points), with the Blues boasting a superior goal difference.
And while they will be hoping the Bantams' continue their dramatic slump in form - six defeats in seven matches - when they travel to seventh-placed Charlton (47) tonight, they won't be able to benefit too much.
The Addicks will be the main winners if that's the case - with Karl Robinson's side guaranteed to claim sixth place with victory at The Valley.
Any shift in the play-off-chasing standings will be carefully watched by Rotherham, who sit comfortably in fifth on 53 points.
They'll be keen to keep the chasing pack at bay when they host Oxford (41), who are 12th.
But with the New York Stadium side eyeing a fifth straight win, the Millers' main attention will be on fourth spot.
A win or draw for them can see them overtake Scunthorpe (54), who have produced a mixed bag in recent weeks.
Scunny travel to a Peterborough side who have only one league win in their past six fixtures.
The Posh sit immediately below Pompey in ninth (44) with a game in hand.
Also on 44 points are Plymouth - a side clearly on the rise following one defeat in their past 12 games.
They'll be keen to leapfrog the Blues in the table when they play host to Wimbledon, who sit 20th in the table on 34 points.
And there's every chance they will with the Dons on a three-match losing run.
Buoyed by the signing of Kyle Bennett, Bristol Rovers (11th on 42 points) will also have their eyes on events at Fratton Park tonight.
They can close the gap on Kenny Jackett's side to one point if they overcome second-from-bottom Rochdale at the Memorial Ground.
Gillingham (41), who sit 13th, will also have Pompey in their sights.
They take on a Northampton outfit with an identity crisis.
But the Gills, too, have stuttered lately, with a four-match winning run being stopped by Wigan and Peterborough.
Paul Cook's Latics should extend their lead at the top of the table when they host Blackpool (19th).
Meanwhile, Shrewsbury (second on 61 points) look a good bet to return to winning ways when they travel to a Fleetwood side who are 17th and without a point in four outings.
In tonight's other games, Bury will look to climb off the bottom of the table when they host Southend (14th).
Walsall host Doncaster, while Oldham and MK Dons will fight it out at Boundary Park.