The Posh currently sit in third place, two points behind Hull City, but with two games in hand. Meanwhile, Gillingham find themselves in 14th position, but could move to within four points of the play-off places with a win.
Defender Ronnie Edwards is a long-term absentee for the Posh after suffering a thigh strain at the end of January.
Gillingham (potential 4-4-2): Bonham - Jackson, Cundy, Tucker, Ogilvie - Dempsey, O'Keefe, Lee, O'Connor - Oliver, Akinde.
Peterborough (potential 3-4-1-2): Pym - Kent, Thompson, Beevers - Ward, Taylor, Brown, Butler - Szmodics - Eisa, Clarke-Harris.
Gillingham have managed two wins, two draws and one defeat in their last five matches. Their most recent game saw a 3-2 away victory over Charlton Athletic, with a goal of the season contender from Connor Ogilvie sandwiched in between efforts from Oliver Lee and Kyle Dempsey.
The Gills' last three victories have come against sides challenging for the play-offs, but they may find Peterborough a more difficult task to overcome.
Peterborough will be hoping to extend their winning streak to three games following two strong results against Ipswich Town and Crewe Alexandra. Darren Ferguson's side did have some patchy form towards the end of January where they drew to struggling Bristol Rovers and lost to Shrewsbury Town, but they appear to be back to their normal standards.
They also have had the benefit of a longer rest period as their weekend match away to Blackpool was postponed due to a frozen pitch.
Ones to watch
Gills captain Kyle Dempsey is the one to watch for the Kent side. The midfielder has contributed six goals and three assists in the league this season, with his tireless work rate and dynamism making him a constant threat throughout.
Meanwhile, Jonson Clarke-Harris is undoubtedly the one to watch for Peterborough. The striker is currently sitting third in the League One goalscoring charts with 15 efforts. Only Charlie Wyke and Luke Jephcott are ahead of him, and he's managed to find the net in his last three games in all competitions.
This match will be the first encounter between the sides this season, with their last fixture resulting in a 0-0 draw in January 2020. The reverse fixture that season saw Peterborough come out on top in a 2-1 win at the Priestfield Stadium. A Joe Ward strike plus a Mo Eisa penalty were enough to give them the three points back in October 2019, even with a late Mikael Mandron goal trying to force a comeback.
In the overall head-to-head record Peterborough come out on top with 17 wins compared to Gillingham's 14. Draws make up the majority of the outcomes though, with there being 21 occasions where the sides have shared the spoils.
How to watch
The game has not been selected for TV coverage in the UK, but an iFollow pass can be purchased for £10 via either club’s website to stream the game live.
Kick-off is scheduled for 18:00 GMT.
"Chairman Darragh MacAnthony gives his managers every tool they ask for and that is why they were the biggest spenders in the transfer market last summer.
"[They have] good players in every position and mostly an equal back up if they go out injured or lose form, so it is going to be a big challenge for us."
Peterborough manager Darren Ferguson, speaking to the club's YouTube channel, said: "They [Gillingham] are very, very good at what they do in terms of how they play.
"That is their real strength, so we have just got to go there and hopefully implement what we want to do to them, and make sure we stop them having the control that they like to get in certain ways."