With Pompey unbeaten at Fratton Park in the league and Oxford on a fantastic run of form, something surely has to give on Saturday.
Wycombe and Sunderland are the only other sides in the division yet to have tasted defeat on their own turf this term.
But their opponents will head to the south coast full of confidence and sitting fifth in the current third tier standings.
They have dropped a mere four points from the past eight League One fixtures, although have just two victories on the road.
One of those, however, was a 6-0 rout of Lincoln in September, which saw in-form Tariqe Fosu net a hat-trick.
Karl Robinson’s men are not just impressing in the league, though, with an exciting quarter-final clash with Manchester City in the Carabao Cup to be played next month.
Having already thrashed top-flight West Ham 4-0, they reached the last eight by beating Sunderland on penalties on Tuesday night.
Their FA Cup adventure begins with a trip to Hayes & Yeading next weekend, while Leasing.com Trophy progress has already been assured.
They missed out on top spot in the group, though, with Pompey claiming that honour by winning a bonus-point penalty shoot-out following October’s 2-2 draw.
Brett Pitman is still doubtful after missing the past three games with a groin problem, but Andy Cannon has shaken off a knock and is available.
Oli Hawkins (foot), Bryn Morris (groin) and Jack Whatmough (knee) are definitely all missing for the Blues.
Oxford will be without Jamie Hanson (hamstring), Rob Hall (ankle), Malachi Napa (leg), former Pompey loanee George Thorne (shoulder) and Ben Woodburn (foot).
The visitors also have fitness concerns over Cameron Brannagan (knee) and Chris Cadden (hamstring), while Fosu missed training on Thursday.
HEAD TO HEAD
Pompey: 25 wins
Oxford: 22 wins
At Fratton Park
Pompey: 17 wins
Oxford: 4 wins
Referee: Ben Toner
Assistants: John Flynn and Mark Derrien
Fourth Official: Ryan Atkin
Overseas subscribers and match pass holders can watch the action and commentary will begin from around 10 minutes before kick-off.
ALSO IN LEAGUE ONE
All games kick-off at 3pm
AFC Wimbledon v Lincoln
Blackpool v Peterborough
Bolton v Fleetwood
Coventry v Accrington
Doncaster v Burton
Gillingham v Rotherham
MK Dons v Tranmere
Rochdale v Bristol Rovers
Sunderland v Southend
Wycombe v Shrewsbury
LAST FRATTON MEETING