The Albion skipper, and longest-serving player, is missing from the Europa League squad to face AEK Athens after it was speculated on social media that he picked up a knock.
His absence means Brazil defender Igor Julio will make his debut. The 25-year-old is one of seven changes from the 3-1 win at Manchester United on Saturday (September 16).
Also missing from the squad is 18-year-old Evan Ferguson. The Irishman didn’t play for his country in the international break due to an injury but came on a late-substitution at Old Trafford.
Ansu Fati, another late sub on Saturday, will make his full debut tonight. Also brought into the starting Xl is James Milner, Pevis Estupinan, Solly March, Billy Gilmour and Joao Pedro.
Joel Veltman, Tariq Lamptey, Mahmoud Dahoud, Simon Adingra, Adam Lallana and Danny Welbeck all drop to the bench. The only players to keep their place in the team are Jason Steele, Jan van Hecke, Pascal Gross and Kaoru Mitoma.
Brighton XI: Steele, Milner, Van Hecke, Igor Julio, Estupinan, March, Gilmour, Mitoma, Gross, Fati, Joao Pedro
Subs: Verbruggen, McGill, Lamptey, Webster, Dahoud, Lallana, Welbeck, Baleba, Adingra, Veltman, Bounanotte, Hinshelwood
AEK Athens XI: Stankovic, Szymanski, Amrabat, Jonsson, Garcia, Gacinovic, Araujo, Pineda, Mitoglou, Hajsafi, Sidibe
Subs: Athanasiadis, Theocharis, Mohammadi, Zuber, Rota, Pronce, Eliasson, Mantalos, Galanopoulos, Pizarro