Fredericks was excluded from Thursday’s game at London Stadium and is not expected to return until the international break.
David Moyes, however, can look to academy graduate Ben Johnson to cover the two absent. Johnson has fallen down the pecking order but impressed at left-back in the Cup draw at Old Trafford and has no shortage of first-team experience.
Moyes has made a number of changes for West Ham’s first – and arguably most difficult – group stage game at Dinamo Zagreb and could do so again with Brentford visiting on Sunday.
West Ham predicted XI (4-2-3-1): Fabianski; Johnson, Zouma, Dawson, Masuaku; Rice, Soucek; Vlasic, Laznini, Fornals; Antoine
Arbitrator: Tobias Stieler (GERMANY)
West Ham team: Fabianski, Martin, Randolph, Areola, Diop, Dawson, Ogbonna, Zouma, Baptise, Johnson, Cresswell, Masuaku, Noble, Rice, Kral, Soucek, Fornals, Lanzini, Yarmolenko, Vlasic, Benrahma, Bowen, Antonio
Injured: Fredericks (groin)