With just two games left to play this season, Pompey are clinging on to the final League One play-off spot.
And Tom Naylor knows that they will likely have to win both of them if the campaign is to be extended.
A first trip to the new Plough Lane is the next test on Saturday, with the Blues taking on an AFC Wimbledon outfit who have almost secured their third tier status for another year.
But Naylor knows it will be difficult against a side who are currently enjoying a six-match unbeaten run.
Pompey’s skipper said: “It’s a huge game and we’re looking to win it, then hope it’s still in our hands the following weekend.
“We need to pick up six points and hope that Charlton drop some – hopefully that’s exactly what will happen.
"It’s a huge game and we’re looking to win it, then hope it’s still in our hands the following weekend."
“It’s an exciting time for the club because these are the matches that are going to make or break your season.
“All the players want to be involved in them and we’ll do everything we can to get into the play-offs and have a chance of securing promotion.
“But AFC Wimbledon have picked up some good form of late and are going to be really difficult opponents.
“It’s a new stadium for me to visit, so I’m looking forward to playing there and trying to collect all three points.”
Naylor has backed this weekend’s social media boycott, which will see clubs stay off Twitter, Facebook and Instagram to protest against online abuse.
He said: “Some of the stuff you see on there is simply not acceptable and it’s nice for football to come together and make a stand.
“Hopefully this can have some sort of positive impact and it’s action that we’re only too happy to support.”