Emiliano Martinez will make his Chelsea debut immediately after signing for the club in a £7.5m deal from Aston Villa.
Chelsea confirmed the deal on Sunday morning, but uncertainty surrounded the time of the deal and the Premier League deadline ahead of this afternoon's clash with Brighton at Stamford Bridge.
But Martinez has been thrown into the line-up, with Mike Penders, who started against Luton in the Carabao Cup midweek, on the bench and the error-prone Robert Sanchez not in the squad and now facing an uncertain three days before Tuesday's deadline.
Chelsea v Brighton LIVE: Emi Martinez makes debut as Enzo Fernandez left out again in Premier League clash
Alonso has also left out Enzo Fernandez, with a move to Man City still in the works.
Chelsea XI: Martinez; Fofana, Lacroix, Colwill (c); Neto, Gusto, Lavia, Hato; Palmer, Rogers; Joao Pedro
Chelsea substitutes: Penders, James, Acheampong, Chavarria, Caicedo, Barco, Gittens, Estevao Willian, Welbeck.
