Arsenal are hopeful of welcoming back Emile Smith Rowe, who missed the loss at Everton with a tight groin.
Gabriel Martinelli is ruled out with the hamstring injury sustained at Goodison Park.
New signing Willy Caballero is poised to make his Southampton debut in goal, with Alex McCarthy ruled out for up to a month because of a hamstring injury.
Fellow goalkeeper Fraser Forster is already sidelined, while Oriol Romeu and Mohamed Salisu are suspended.
Jan Bednarek is available but Che Adams will be assessed for a training ground injury and Stuart Armstrong remains out.