Liverpool will be without midfielders Jordan Henderson and Stefan Bajcetic for the second leg of their Champions League last-16 tie at Real Madrid.
The Reds travel to Spain trailing 5-2 and Henderson has been ruled out through illness while 18-year-old Bajcetic has a thigh injury.
“Stefan, it’s a stress response in his adductor, which is absolutely bad,” said Liverpool boss Jurgen Klopp.
“He doesn’t feel a lot but he is now out for I don’t know exactly how long.”
He added: “We have just to let it settle and then we will see when he can come back.”
Liverpool, who were beaten by Real in last season’s Champions League final, took a 2-0 lead against the Spanish side before losing 5-2 in the first leg at Anfield.
“I said three weeks ago, Madrid with their result are through to the next round, now we are here three weeks later and we know there’s a game to play,” said Klopp.
“If there’s only a one percent chance, I would like to give it a try. We’re here to play an extremely strong opponent and try to win the game.
“As difficult as it is, it’s not likely, but possible. For that, we are here, we’ll see where it leads us to.”
Since the first leg, Liverpool beat Manchester United 7-0 only to lose 1-0 at relegation-battling Bournemouth in their next game, summing up what has been an inconsistent season.
They are sixth in the Premier League and have suffered seven of their eight top-flight defeats away from home.
“If we can surprise ourselves in a negative way we should be able to surprise ourselves in a positive way as well,” added Klopp.
“But it’s clear, we’re not here telling Madrid, ‘be careful, we’re coming’ – that’s not the situation we are in.”
Real striker Karim Benzema missed his side’s league win against Espanyol on Saturday but is fit to face Liverpool.
“The message is quite simple: not to assume,” said Real Madrid manager Carlo Ancelotti.
“The players understand that I think it will be an open match as Liverpool come here trying to change the dynamic.
“We have to do both things, attacking and defending, properly. We will not just defend, we are thinking about the attack.”
He added: “From a psychological level, the match is more complex for us than Liverpool.
“Liverpool come here to give it their all and do their best from minute one, whatever happens. We saw that from the first leg.
“We will try to do all we can from the beginning but we have more questions than the opponent.”