Jurgen Klopp has made a total of seven changes to the side that drew with Aston Villa last weekend, as Kelleher makes his first Premier League start of the season in between the sticks over Alisson Becker.
Milner and Firmino have also been handed starts for their final game in Liverpool shirts, while Joe Gomez, Joel Matip, Kostas Tsimikas and Diogo Jota are also recalled to the first XI.
Mohamed Salah, Trent Alexander-Arnold, Fabinho and Curtis Jones are the only players to hold their places from last weekend, as Ibrahima Konate, Luis Diaz and Cody Gakpo take up spots on the bench.
Meanwhile, outgoing Southampton manager Ruben Selles has made just the one change from last weekend's 3-1 defeat to Brighton & Hove Albion, bringing Kamaldeen Sulemana back in for Joe Aribo in the final third.
Southampton: McCarthy; Bree, Lyanco, Bednarek, Walker-Peters; Lavia, Ward-Prowse; Elyounoussi, Alcaraz, Sulemana; Walcott
Subs: Bazunu, Caleta-Car, Livramento, Doyle, Aribo, S. Armstrong, A. Armstrong, Ballard, Arno-Ameyaw
Liverpool: Kelleher; Alexander-Arnold, Gomez, Matip, Tsimikas; Fabinho, Jones, Milner; Salah, Firmino, Jota
Subs: Adrian, Konate, Henderson, Gakpo, Diaz, Carvalho, Elliott, Arthur, Williams
Dundee Utd 
Celtic 
Valencia 
Alaves 
PSV 
Feyenoord 
Bordeaux 
Rennes 
ST Etienne 
Marseille 
Monaco 
Everton 
Chelsea 
Leicester 
Wolverhampton 
Manchester Utd 
Bournemouth 
Real Madrid 
Sevilla 
Cremonese 
Sampdoria 
Tottenham 
Liverpool 
VFL Wolfsburg 
Borussia Dortmund 
Las Palmas 
Espanyol 
Monza 
Juventus 
Lens 
Paris Saint Germain 
Fiorentina 
Udinese 
Benfica 
Estoril 
Inter 
Como 
Manchester City 
Fulham 
Nottingham Forest 
Motherwell 
ST Mirren 
Rangers 
Carrarese 
Arsenal 
Ipswich 
Cagliari 
Lazio 
Atalanta