Pompey travel to The Valley for the first time in over eleven years for one of their biggest fixtures of the season.
Brett Pitman should return to the starting line-up having missed the last three games but there are doubts that Kal Naismith, Ben Close and Ollie Hawkins will be available for selection.
Addicks boss Karl Robinson is set to make wholesale changes to the side that played in the Checkatrade Trophy last time out. Jason Pearce and Ricky Holmes are set to feature against their former club.
Pompey currently lie in 8th place in League One, six points behind tomorrow's opponents who occupy the final play-off place with a game in hand, too. If Kenny Jackett's team are going to make a serious bid to finish in the top six this season then they can't afford to lose tomorrow.
Whilst the Checkatrade Trophy has been rightly ridiculed this season (with the Blues facing a trip to Stamford Bridge to take on Chelsea B next) it has given Pompey a platform for some of their best performances of the season, having easily beaten Northampton last weekend.
That victory made it five wins in six for Kenny Jackett's men in a run which includes a 1-0 triumph at The Valley in the aforementioned couldn't-care-less Trophy whilst Charlton have only won twice in the same period of time.
Karl Robinson has been bemoaning the fact that his team have had to play so many games in a short space of time so it seems that he has a ready-made excuse if his team are beaten tomorrow.
With Pitman in the side, there's always a chance that Pompey could nick a result in one of their toughest fixtures of the season but Charlton's squad is full of quality players at League One level and the Blues' backline will be kept on their toes by the likes of Mark Mashall and Leon Best. What are the odds on Holmes scoring again?
Pompey will be taking their biggest following of the season to London tomorrow and a win will have them believing that a promotion challenge could become a reality.
A defeat, however, and those same fans will be contemplating a mid-table finish instead. And will that be good enough?
Predicted Starting Line-Ups
GK: Ben AMOS
RB: Ezri KONSA NGOYO
CB: Jason PEARCE
CB: Patrick BAUER
LB: Naby SARR
DM: Ahmed KASHI
DM: Jake FORSTER-CASKEY
RM: Ricky HOLMES
AM: Leon BEST
LM: Mark MARSHALL
CF: Josh MAGENNIS
GK: Luke McGEE
RB: Nathan THOMPSON
CB: Christian BURGESS
CB: Matt CLARKE
LB: Brandan HAUNSTRUP
DM: Danny ROSE
DM: Stuart O'KEEFE
RM: Gareth EVANS
AM: Conor CHAPLIN
LM: Jamal LOWE
CF: Brett PITMAN
Last Time: Charlton Athletic 0 Portsmouth 1 (Premier League - 16/09/2006)
Lomana LuaLua came off the bench scored the only goal of the game to take Pompey to the top of the Premier League and have some of the players talk about the prospects of the Champions League. They ended up finishing 9th that season.
As good as Pompey have been recently, they have still been unconvincing on the road and there seems to be a gap between the top six and the rest of the division. Charlton will probably have too much on the day.
Charlton Athletic 2 Portsmouth 1