The two clashed in the Premier League at the start of October with the Blues needing two late goals to run out 3-1 winners.
The Saints will be out for revenge having been level with 15 minutes remaining before captain James Ward-Prowse was shown a red card.
But they face a tough task to reach the next round and face a Chelsea side who put seven past a helpless Norwich on Saturday.
Chelsea vs Southampton: talkSPORT commentary
The Carabao Cup clash is due to take place on Tuesday, October 26 with kick-off set for 7:45pm.
The fourth-round fixture will be played at Stamford Bridge, London.
talkSPORT will have live coverage of the game from 7:30pm with commentary coming from Joe Shennan and ex-England defender Danny Mills.
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Chelsea vs Southampton: Team news
The Blues have been handed a boost with the news that N'Golo Kante will be fit to return against the Saints.
The Frenchman missed the 7-0 rout over Norwich with muscle tightness but the club revealed his absence was just a precaution.
There is less positive news on Romelu Lukaku and Timo Werner, who are both not ready to return after suffering injuries against Malmo last week.
Christian Pulisic also remains a little away from his own comeback with this cup tie set to come too soon for the American.
Southampton meanwhile will be without Armando Broja - who scored against Burnley - as he is unable to play against his parent club Chelsea.
Ward-Prowse is still suspended from the ban he picked up the last time he faced the Blues and Jack Stephens is again missing due to a knee injury.
Chelsea vs Southampton: What has been said?
Tuchel has already dropped a hint that Callum Hudson-Odoi will feature against Southampton this week.
"He had a good game against Malmo, another good game today," Tuchel said during his post-match press conference.
"There are still things to improve and work on, but it's on him.
"It's like I said before the game, he has to show he has to produce performances like this consistently and it's time to show. Next performance is on Tuesday."