Fredericks has been ruled out of Thursday’s game at the London Stadium and is not expected to return until after the international break.
David Moyes, however, can turn to academy graduate Ben Johnson to cover for both absentees. Johnson has fallen down the pecking order but impressed at left-back during the cup tie at Old Trafford and is not short on first team experience.
Moyes made a number of changes for West Ham’s first – and arguably most difficult – group stage game at Dinamo Zagreb and may 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; Antonio
Referee: Tobias Stieler (GER)
West Ham squad from: 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)