There are three changes to the Chelsea side with Cesar Azpilicueta, Jorginho and Tammy Abraham starting for the Blues.
That trio replace Reece James, Kai Havertz and Olivier Giroud in defence, midfield and attack respectively.
Mason Mount makes his 50th Premier League appearance alongside Jorginho and N'Golo Kante in midfield, with Azpilicueta in possession of the armband in what his first league game since 24 October.
Callum Hudson-Odoi is fit enough for a place on the bench, which has been expanded to nine players following a Premier League meeting last week.
West Ham make a couple of changes to their side, with Fabian Balbuena and Mark Noble coming in for Issa Diop and Said Benrahma.
Chelsea (4-3-3): Mendy; Azpilicueta (c), Zouma, Thiago Silva, Chilwell; Kante, Jorginho, Mount; Pulisic, Abraham, Werner.
Subs: Kepa, Rudiger, Christensen, Emerson, Kovacic, Gilmour, Havertz, Hudson-Odoi, Giroud.
West Ham (4-2-3-1): Fabianski; Coufal, Balbuena, Ogbonna, Cresswell; Rice, Noble (c); Bowen, Soucek, Fornals; Haller.
Subs: Martin, Randolph, Dawson, Diop, Fredericks, Johnson, Snodgrass, Yarmolenko, Benrahma.
The referee is Chris Kavanagh.
Chelsea stats
Chelsea are unbeaten in five Premier League home games (three wins, two draws), scoring 14 goals in that run.
Having gone nine Premier League games unbeaten, we are now hoping to avoid three successive defeats in the competition for the first time since October/November 2015.
Olivier Giroud is now our equal top scorer in all competitions with Timo Werner on eight goals.