Liverpool boss Jurgen Klopp has named three players who can help during the absences of Virgil Van Dijk and Fabinho.
The former has a knee injury that will keep him out for the season.
The latter suffered an injury against Midtjylland on Tuesday in the Champions League.
Klopp hopes youngsters Rhys Williams, Nathaniel Phillips and Billy Koumetio can help in an emergency.
He told reporters: "[Williams] did really well. The only problem we have now is unfortunately we have four days to the West Ham game and you will make every day a story of him and then he has to prove he can deal with that as well because before everything was calm around him. We try to do that as well.
"He's a talent, he plays for England U20s, he's 19 years old. I didn't tell any news when I said he has more Champions League minutes than Premier League minutes because he didn't play in the Premier League yet and has now two Champions League appearances.
"Won both games on top of that, which is pretty exceptional. He did well, everything looks promising.
"Apart from Rhys, we still have Nat Phillips, who for the reason that we thought he might make a transfer to another club, he is not in the Champions League squad, which is strange - but he is a centre-half as well.
"Billy [Koumetio] the kid, I'm not sure if he can train now tomorrow or not but he will be back in training. So, we have very young and inexperienced alternatives, and in the moment it looks like we have to choose one of them.
"I don't know yet. But to be really clear and positive, Rhys was not in one situation tonight our problem, he played a really good game."