The Gunners head into the match on the back of Saturday's 3-0 victory at Aston Villa in the Premier League - a result that saw them end a winless run of three games.
Arsene Wenger's side reached the fourth round of last season's competition before suffering a 2-0 defeat at home to London rivals Chelsea.
Meanwhile, Southampton travel to the capital full of confidence thanks to an impressive run of four straight wins in all competitions.
Three of those victories have come in the Premier League, moving the Saints up to second place in the table.
The hosts, who are still without Mathieu Debuchy, Theo Walcott, Olivier Giroud and Jack Wilshere, are expected to rest a number of first-team players for the match. James Ward-Prowse and Maya Yoshida are both doubts for the Saints, though the pair are expected to be available.
Possible starting lineups
Arsenal: Ospina; Bellerin, Chambers, Mertesacker, Gibbs; Arteta, Rosicky; Oxlade-Chamberlain, Ozil, Podolski; Welbeck
Southampton: Forster; Clyne, Yoshida, Fonte, Bertrand; Schneiderlin, Cork, Ward-Prowse, Tadic; Long, Pelle
Sports Mole says: 2-1