Roberto Firmino will also be absent against Spanish champions at Anfield, leaving Klopp without two of his most potent attacking weapons.
Liverpool: Liverpool must turn to unlikely heroes to overturn a 3-0 Champions League semi-final, first leg deficit against Barcelona on Tuesday, according to defender Trent Alexander-Arnold after Mohamed Salah was ruled out with a concussion.
Roberto Firmino will also be absent against the Spanish champions at Anfield, leaving Jurgen Klopp without two of his most potent attacking weapons for what is already a massive challenge.
"Obviously we've got two of our main goalscorers out, but it also presents an opportunity for some of the other lads to come in, make a name for themselves and make themselves heroes," said Alexander-Arnold.
"If we do overturn the deficit tomorrow then whoever scores, their name will always be remembered because I am sure it will be one of those really special nights."
Salah was stretchered off during Liverpool's tense 3-2 win at Newcastle on Saturday that kept alive their chances of a first Premier League title in 29 years after colliding with Magpies' goalkeeper Martin Dubravka.
"It's a concussion so that means he would not even be allowed to play," Klopp said on Monday.
"He feels OK but it is not good enough from a medical point of view that is all. He's desperate (to play) but we cannot do it."
Klopp, speaking before Manchester City ensured they remain in the driving seat for the Premier League title by beating Leicester 1-0 on Monday, was realistic about his side's chances of progressing to a second consecutive Champions League final.
But the German refused to give up hope. "Together with our supporters it was a long season and there is at least a little chance to make it even longer," Klopp added.
"Two of the world's best strikers are not available tomorrow night and we have to score four goals against Barcelona to go through after 90 minutes.
"It doesn't make life easier, but as long as we have 11 players on the pitch, we will try it."
Luis Suarez scored the opening goal against his former club in last week's first leg at the Camp Nou, but ahead of his return to Anfield, the Uruguayan warned his current teammates of the lift playing on home soil will give Liverpool.
"To play at Anfield is like playing with an extra man for what the fans transmit to the Liverpool players," said Suarez.
And Barcelona coach Ernesto Valverde believes attack will be the best form of defence as if the Catalans get an away goal, Liverpool will need to score five.
"What we have to do is score," said Valverde.
Suarez will be joined by Lionel Messi and Philippe Coutinho on his return to Anfield after a 142 million pounds (USD 186.5 million) move to Barca from Liverpool last year.
But the often-injured Ousmane Dembele is absent for the visitors due to a hamstring problem and Valverde believes the Frenchman's absence will be felt just as much as Salah and Firmino.
"We don't want any player to be injured. It would have been extraordinary to see them all on the field. They are all important," he said.
"Dembele's absence is a problem. Against a team that concedes space (in behind) it is always important to have player like Ousmane."