The Blues have dropped points in their past two League One matches and dropped to sixth in the table.
A 1-1 draw with Oxford United was followed up with a 1-0 loss at Blackpool on Tuesday night.
Kenny Jackett’s side lacked any sort of attacking potency, despite being top scorers in the division with 26 goals.
The likes of Ronan Curtis, Ryan Williams and Andy Cannon struggled to impact the game, while John Marquis squandered a couple of decent chances.
Now Pompey gear up to face a Peterborough side who are also vying for automatic promotion.
Jackett has to weigh up whether he makes changes to his starting XI from that Bloomfield Road defeat or stick with the team that has been successful in previous games.
Here’s how we think Pompey will line-up...
1. Goalkeeper - Craig MacGillivray
The Scot will be frustrated with the lack of clean sheets Pompey have been keeping of late. It's been eight matches since MacGillivray recorded a shutout and he faces tall order to ensure Peterborough don't bag. Photo: PinPeP
2. Right-back - Callum Johnson
The defender will have to be on his mettle to repel Posh's Siriki Dembele - who's widely recognised as one of the best players in the league. Photo: Joe Pepler
3. Centre-back - Jack Whatmough
It was at Peterborough in March when the Gosport lad made his first league start for more than a year and was given a tough afternoon. However, Whatmough's been immense this season and will be relishing the battle with Jonson Clarke-Harris. Photo: Robin Jones
4. Centre-back - Sean Raggett
Was one of Pompey's standout performers at Blackpool on Tuesday night. Always puts his body on the line and starting to find some real rhythm Photo: Graham Hunt