N’Golo Kante was passed fit to play aat Southampton despite struggling with an ankle problem in recent weeks.
Callum Hudson-Odoi has been handed a start as he steps up his match fitness following five months out while Tammy Abraham and Willian have kept their spots after goalscoring performances in Lille.
Reece James made an encouraging Champions League debut but the 19-year-old drops out. Barkley, who was left out of the matchday squad in the week, returns to the bench.
Frank Lampard is without Emerson Palmieri, Antonio Rudiger and Ruben Loftus-Cheek.
Confirmed starting lineups
Southampton: Gunn, Valery, Bednarek, Yoshida, Bertrand, Romeu, Hojbjerg, Ward-Prowse, Redmond, Ings, Long.
Subs: McCarthy, Stephens, Adams, Armstrong, Boufal, Obafemi, Danso.
Chelsea: Arrizabalaga, Azpilicueta, Zouma, Tomori, Alonso, Kante, Jorginho, Willian, Mount, Hudson-Odoi, Abraham.
Subs: Christensen, Barkley, Caballero, Kovacic, Pulisic, Batshuayi, James.
