A visibly upset Jurgen Klopp said Liverpool's Harvey Elliott was in "massive pain" after suffering a serious ankle injury at Leeds.
Elliott, 18, was carried off on a stretcher and taken to hospital following a challenge by Leeds defender Pascal Struijk, who was sent off.
Klopp said Elliott had dislocated his ankle during Liverpool's 3-0 win.
"We'll play without him, but we will wait for him as well because he is a top player," added the Liverpool boss.
The former Fulham teenager posted a message on Instagram after the Elland Road encounter, saying he is "on the road to recovery" and Liverpool added later on Sunday that he had been discharged from hospital but will need to undergo surgery in the coming days.
"Harvey, his family and Liverpool FC would like to place on record their thanks to the paramedics and all the staff at Leeds General Infirmary for the care and treatment given," the club said in a statement.
'It looked bad'
Liverpool forward Mohamed Salah, who had earlier scored his 100th Premier League goal, was closest to Elliott when the incident happened and immediately called for the medical staff after seeing his team-mate in pain.
Salah looked visibly upset and covered his eyes in distress.
"I saw the situation," said Klopp. "I could see his foot was not in the right place. That is why we were all shocked."
Speaking to BBC Match of the Day, he added: "Massive pain, shock for him, for us and we don't know more. We have to wait.
"I cannot feel the game anymore. Harvey overshadows everything."
Reds captain Virgil can Dijk said: "From the moment it happened, you saw Mohamed Salah shouting to the side. You look at the reaction of Harvey and you know it is really serious."
Van Dijk missed most of last season with a serious knee injury himself and said everyone at Liverpool would have "Harvey's back" during his recovery.
"We will see the outcome, then pray and hope the best for him," added the Netherlands defender.
"I have experience with all the staff, players and fans that they have your back and I am 100% sure we will be there for him. Our club Liverpool will be there for him no matter what."
Players covered their eyes during distressing scenes at Elland Road'I regret dearly what happened'
Elliott, who joined Liverpool in July 2019 from Fulham at the age of 16, applauded the fans while being carried off and taking on oxygen.
The player, who made his Liverpool debut in September 2019, has featured in every game for Klopp's side in the Premier League so far this season.
Belgian Struijk, a first-half substitute for the injured Diego Llorente, was dismissed on the hour for what refereeing body PGMOL said was "serious foul play due to the intensity of the challenge and endangerment to Elliott".
Leeds boss Marcelo Bielsa said he "regretted dearly what happened" to the Reds youngster.
Bielsa 'regrets' serious injury suffered by Liverpool's Elliott"I wish it did not happen," added the Argentine.
"For that to happen to any player is saddening. For a young player, playing at a high level, even more. I am sure my player did not have the intention to harm him in any way.
"In no way did he provoke any harm to the opponent."
'Speedy recovery kid' - how social media reacted
