England's Alex Oxlade-Chamberlain will miss the World Cup this summer after injuring a knee during Liverpool's Champions League tie against Roma.
The 24-year-old midfielder was taken off on a stretcher in the 15th minute of Tuesday's match at Anfield after challenging Aleksandar Kolarov.
He had a scan on Wednesday which revealed a knee ligament injury.
"Absolutely devastated to have picked up this injury at such a crucial time," said Oxlade-Chamberlain.
He also said the injury "pales in comparison" to the news of a man being left in a critical condition after being attack outside Anfield before the match.
It is understood Oxlade-Chamberlain spoke to England manager Gareth Southgate to inform him about the injury.
"The extent of the injury means Oxlade-Chamberlain is set to miss the remainder of the campaign for Liverpool, as well as the World Cup in Russia with England," Liverpool said in a statement.
"Oxlade-Chamberlain will now begin a rehabilitation programme to enable him to reach full fitness again as soon as possible, returning to action next season."
The Reds added there would be "no specific timescale" on the former Arsenal player's return.
Oxlade-Chamberlain, capped 32 times, joined the Anfield side from the Gunners last summer for £35m and has made 41 appearances in all competitions, scoring five goals.
Liverpool beat Roma 5-2 in the first leg of their Champions League semi-final tie, with the return leg in Italy next Wednesday.
England will face Belgium, Panama and Tunisia in Group G at the World Cup, which begins on 14 June.
Oxlade-Chamberlain statement in full:
"Absolutely devastated to have picked up this injury at such a crucial time in the season. Gutted I won't be able to play any further part now in our Champions League run for Liverpool, and also the World Cup with England.
"But now it's all about supporting the boys and getting behind them. I know we have what it takes to do something special in this tournament. I'm going to give everything I have to make sure I'm back as quickly as possible.
"However, this all pales in comparison to how the family of the Liverpool fan badly hurt before last night's game must be feeling. My thoughts are with him and his loved ones. Thank you for all your kind words, messages and support. I'll see you soon. #YNWA."