Jurgen Klopp has named seven players that could partner Joe Gomez at centre-half on Saturday against West Ham.
Fabinho was added to Liverpool’s list of centre-half injuries on Tuesday night, leaving Gomez as Klopp’s only senior centre-half.
Nat Phillips, Billy Koumetio and Rhys Williams are the options from within the club’s youth system, but Klopp named four first-team players who can play out of position.
Klopp does appear to be leaning towards Phillips as he was on loan at Stuttgart last season, but he was close to leaving in the summer.
“I know Nat [Phillips] the longest so I was really happy with this development. Since I know him he made big, big steps and is an exceptional character,” said Klopp.
“I said it before that the little problem was that we were all convinced, how it looked all the time…there were a lot of clubs interested in him and in the end, maybe because of the coronavirus crisis, nobody had the money to do it but we expected him to leave the club, to be honest.
“Thank God he didn’t, but that’s the reason why he is not in the Champions League squad, the only reason.
“He cannot be on the bench in the Champions League but he is available for the Premier League like all three are and now I have to make a decision.
“And we have still, obviously, other options like Hendo or Gini or James – or Robbo can play centre-half as well. They are all not smaller than Mascherano, for example, and he played pretty well in that position.
“So yes, we have obviously still one or two options and one of them, we will choose. Which one, you have to switch on the television tomorrow night.”
Henderson has previously played for Liverpool at centre-half but Robertson has never played a senior game there.