Pompey can expect Ralph Hasenhuttl will play his ‘best possible side’ when Southampton travel to Fratton Park in the Carabao Cup.
The Blues’ south-coast rivals make the trip along the M27 on Tuesday night for the first meeting between the sides since 2012.
Both sets of fans are looking forward to the clash, with Fratton Park completely sold out for the third-round game.
And with local bragging rights at stake, focus will be on the starting line-ups for the highly-anticipated match-up.
With Pompey boss Kenny Jackett keen to kick-start a campaign that has seen his side struggle in the league to date, a strong Blues starting XI can be expected for such an important clash.
Hasenhuttl admitted he has been reminded by Southampton fans of the significance the game – despite their current Premier League status.
At present, Saints sit 10th in the top tier and are unbeaten in their past three top-flight games.
They host Bournemouth tonight, before travelling to Spurs in the Premier League on Saturday, September 28.
Both outings represent key games.
But Hasenhuttl insisted he’s not interested in rotating any of his players to save their freshness at this stage of the season.
He wants to win every game and will ‘pick the best possible side’ for the trip to Fratton Park.
The Southampton manager said: ‘It is hard not to think about (the Portsmouth cup tie) because everywhere you come, the fans are telling you how important it is.
‘They can be sure we know it is an interesting game, but first we have to focus on the Premier League game against Bournemouth.
‘What I can say is that I don’t think about any rotation to save a player for the Tuesday game, we have enough time between, then enough before the game against Tottenham.
‘As always, we try to pick the best possible side for us. Every game is important and we try to win every one.’