You have to go back to the 2011/12 campaign to find the last time that Pompey met their south coast rivals.
Both games during that Championship campaign finished all squad – although it was certainly the Blues fans who felt more like celebrating following the final whistle.
Joel Ward and David Norris both wrote their names in Fratton folklore by grabbing dramatic equalisers.
The latter’s is certainly the most memorable, with a superb volley deep into stoppage-time at a stunned St Mary’s.
But Southampton secured promotion at the end of that season and have remained in the Premier League since, despite a couple of recent flirtations with the drop.
And Pompey – who were then deep in financial crisis – were relegated, still trying to negotiate their way back up the divisions.
Both teams enter the game on the back of league setbacks, with Ralph Hasenhüttl’s men beaten by neighbours Bournemouth on Friday night.
It leaves them 13th in the top-flight table and that clash with the Cherries was labelled a derby by some.
Supporters of a Pompey or Southampton persuasion, however, know that this is the only true south coast derby.
TEAM NEWS
Tom Naylor will require a fitness test after collecting a knock at Wycombe, while Ellis Harrison’s red card sees him serve a one-match ban.
Pompey are also without the injured quartet of Lee Brown (Achilles), Marcus Harness (thigh), Bryn Morris (groin) and Jack Whatmough (knee).
Moussa Djenepo is missing for the visitors with a muscle injury in his leg, while there are doubts over the fitness of Nathan Redmond (ankle).
VIEW FROM THE DRESSING ROOM
Read the thoughts of Kenny Jackett and Ben Close or register for a free iFollow account to watch the below videos.
HEAD TO HEAD*
Overall
Pompey: 9 wins
Southampton: 19 wins
10 draws
At Fratton Park
Pompey: 4 wins
Southampton: 8 wins
5 draws
*Football League/FA Cup/League Cup matches only
TICKETS
There are no seats available for this game, so please do not travel to the ground if you do not have a ticket.
Turnstiles are open from 6.15pm this evening, while fans will be able to use the Victory Bar from 4.30pm.
Please note that the car park is full for this game and there are no more spaces available.
For a full list of ticketing and access information for tonight’s match, please click on the link to the left.
OFFICIALS
Referee: Kevin Friend
Assistants: Matthew Wilkes, Mark Scholes
Fourth Official: Dean Whitestone
MATCH COVERAGE
iFollow subscribers and audio match pass holders can listen to live commentary from Chris Wise and Guy Whittingham by signing into their account and visiting the match centre from 7pm this evening.
Please note that Carabao Cup matches are not available to watch live on iFollow, either by overseas or domestic supporters.
Viewers in the UK can watch the game live on Sky Sports Football, while overseas supporters should check their local listings.
Click here for more information about using iFollow on a matchday and click here for information on downloading the app, so you can access content on your mobile device.
We will have updates throughout the game on Twitter and the match centre. You can also see behind-the-scenes content on our Instagram story.
There will be post-match reaction on the website, iFollow and our official YouTube channel, with highlights to follow on Wednesday.
Local listeners can hear commentary by tuning in to either Express FM or BBC Radio Solent.
BETTING
The visitors are the 4/11 favourites with Sky Bet to reach the fourth round, while Pompey can be backed at 2/1.
Click here to read our full betting guide and visit www.skybet.com/pompey to earn money for the club when you place a bet. Please gamble responsibly.
ALSO IN CARABAO CUP
Games kick-off at 7.45pm unless stated
Tonight
Arsenal v Nottingham Forest
Colchester v Tottenham
Crawley v Stoke
Luton v Leicester
Preston v Manchester City
Sheffield Wednesday v Everton
Watford v Swansea
Wednesday
Brighton v Aston Villa
Burton v Bournemouth
Chelsea v Grimsby
MK Dons v Liverpool
Oxford v West Ham
Sheffield United v Sunderland
Wolves v Reading
Manchester United v Rochdale (8pm)
MAGIC MOMENT
👀 Something to get you in the mood for tomorrow...
— Portsmouth FC (@Pompey) September 23, 2019
⚽️ Your Goal of the Day comes courtesy of @DMNorris19#Pompey pic.twitter.com/g0gFOv8m2Y