Jack Ross is hopeful Sunderland can steal a 'psychological' advantage over Pompey in the battle for League One glory.
Kenny Jackett’s table-toppers will be knocked off the summit should the Black Cats – the Blues’ nearest rivals – overcome Wycombe Wanderers at home on Saturday.
Pompey are without a game this weekend, after their scheduled meeting with Charlton at Fratton Park was postponed because of the number of Addicks players on international duty.
That means Sunderland, currently three points behind in second place, will go top on goal difference should they beat Wycombe.
The Blues’ goal difference currently sits at +14, with Sunderland on +19.
And Black Cats boss Ross believes it would give his side a well-timed boost in their bid to claim the title.
He told chroniclelive.com: 'It would be a step forward, psychologically it would be be other good reward for the players.
'The size of the club means we have been there to be shot at all season, so I don't think it makes much difference.
'The only time it really matters is the latter stage of the season.
'It would be a nice boost for us to go that extra place and lead from the front.
'We want to be top, I have never shied away from that from day one of being here.
'That’s not because I think we have a divine right to be there, every game has been incredibly difficult.'