With Lukas Fabianski back in training but still a way off being match fit, third choiceDavid Martin, 33, will make his debut at Stamford Bridge.
Roberto has been in woeful form since coming in to replace Fabianski, including effectively throwing the ball into his own net to round off a 3-0 defeat at Burnley.
For Chelsea, managerFrank Lampardhas broughtOlivier Giroudback in from the cold in place of the injured Tammy Abraham after the England striker picked up a hip injury during Wednesday night’s hectic Champions League group group draw in Valencia.
Giroud, who had fallen to third in the pecking order under Lampard this season, has only started one Premier League game for Chelsea so far, coming off the bench in a further three. )
Chelsea: Arrizabalaga, James, Zouma, Tomori, Emerson Palmieri, Jorginho, Kovacic, Pedro, Mount, Pulisic, Giroud
Subs: Christensen, Kante, Willian, Caballero, Hudson-Odoi, Batshuayi, Azpilicueta
West Ham: Martin, Fredericks, Ogbonna, Balbuena, Cresswell, Rice, Snodgrass, Noble, Fornals, Felipe Anderson, Antonio
Subs: Zabaleta, Yarmolenko, Roberto, Sanchez, Haller, Masuaku, Ajeti
Referee: Jonathan Moss