There are just two games remaining for Pompey to claim a play-off spot and ensure their season is extended beyond May 9.
And the first of them sees a maiden trip to the new Plough Lane to take on AFC Wimbledon on Saturday (3pm kick-off).
While the visitors are trying to reach the Championship, their opponents want to secure their third tier status for another campaign.
It looks as though they have already done enough, though, with a six-point gap to Rochdale and Northampton in the drop zone and a superior goal difference over both sides.
They were in the bottom four following a home defeat to Fleetwood on Easter Monday – but that is the last time the Dons have tasted defeat.
Head coach Mark Robinson – who replaced Glyn Hodges in January – has guided the side to a six-match unbeaten run that includes four victories.
Like Pompey, they were involved in a six-goal thriller earlier in the week, with Joe Pigott’s stoppage-time strike earning a point against struggling Rochdale.
Goals from John Marquis, Ryan Williams, Sean Raggett and Ben Close secured a 4-0 Blues victory when the sides met on the south coast earlier in the season.
But a late Terell Thomas header ensured Wimbledon took all three points in the most recent away meeting – which took place at Kingsmeadow – last term.
Alex Bass (foot), Ellis Harrison (knee) and Michael Jacobs (knee) are all out, while Jack Whatmough completes a four-match ban.
But Lee Brown is available again following a hamstring problem, while Jordy Hiwula (ankle) has returned to training.
Callum Reilly (ankle) is sidelined for the hosts, while there are doubts over the fitness of Ethan Chislett (Achilles) and Darnell Johnson (ankle).
HEAD TO HEAD*
Pompey: 18 wins
Wimbledon: 14 wins
Pompey: 6 wins
Wimbledon: 10 wins
*Includes matches against Wimbledon FC
Referee: Charles Breakspear
Assistants: Michael Webb and Andy Bennett
Fourth Official: Conor Farrell
Supporters in the UK can watch the action live – with graphics, commentary and replays – by purchasing a match pass for £10.
Please note that subscribers based in the UK and Ireland will still need to purchase a match pass in order to watch the game live.
There will be post-match reaction on the website and our official YouTube channel, with highlights to follow on Sunday.
ALSO IN LEAGUE ONE
All games kick-off at 3pm
Accrington v Charlton
Bristol Rovers v Crewe
Burton v Gillingham
Fleetwood v MK Dons
Hull v Wigan
Northampton v Blackpool
Peterborough v Lincoln
Plymouth v Sunderland
Rochdale v Doncaster
Shrewsbury v Oxford
Swindon v Ipswich