Benoit Badiashile, Noni Madueke, Pierre-Emerick Aubameyang and David Fofana are back in contention for Chelsea, having been ineligible to face Borussia Dortmund.
Wesley Fofana, Denis Zakaria and Mateo Kovacic returned to the matchday squad in midweek after overcoming injuries.
First-team coach Ruben Selles will take charge of Southampton following the departure of manager Nathan Jones.
Saints will assess right-back Kyle Walker-Peters, who has missed the last two games with a hamstring issue.
CHRIS SUTTON'S PREDICTION
Chelsea boss Graham Potter really has to win this game because otherwise he is going to come under massive pressure.