The game against two of the division’s true heavyweight clubs is a sell-out – although with snow falling thick and fast in south Yorkshire in recent days, it’s not clear how many of the Owls’ anticipated 1,600 travelling supporters will actually make it down to PO4.
Those weather conditions forced the Wednesday team to change their departure time for the journey to Portsmouth.
It also impacted their pre-match preparations as the roof of the league leaders’ indoor training facility collapsed.
It means Darren Moore and his side will not be prepared as they would have liked for today’s game – but will it have any barring on the result?
Pompey are unbeaten at home under John Mousinho. Meanwhile, there’s a new-found confidence about the Blues, despite Tuesday’s night’s defeat at Barnsley.
The hosts will go into the fixture as underdogs given the Owls’ 21-match unbeaten run in the division.
But is there a prospect of a surprise given the circumstances heading into the game?
Here’s what the statistical experts at thirtyeightfive.com believe will be the outcome, plus their predictions for the rest of today’s League One programme.