Nine points separate the 11th-placed Blues and the Tykes, who currently occupy sixth place and the last League One play-off place.
Victory would see John Mousinho’s side reduce that deficit to six points.
Anything else and it’s becoming difficult to see Pompey making up that ground, despite 19 games left to play.
Indeed, the Blues would require teams above them to start dropping significant points as we quickly approach the business end of the season.
A win is therefore a must today for new-look Pompey, who signed both Di’Shon Beranrd and Paddy Lane on transfer deadline day.
But how do the so-called data experts at FiveThirtyEight see today’s game at Fratton Park going and this afternoon’s other League One games?
Here’s what we discovered...

5. Cambridge United v Ipswich Town
Cambridge United win: 14%. Ipswich Town win: 65%. Draw: 21%. Photo: Stephen Pond

6. Derby County v Morecambe
Derby County win: 69%. Morecambe win: 11%. Draw: 20%. Photo: Gareth Copley


8. Fleetwood v Burton Albion
Fleetwood win: 52%. Burton Albion win: 24%. Draw: 24%. Photo: Henry Browne

