The midfielder was forced out from the field after 18 minutes of Liverpool’s 5-2 victory in the Champions League semi-final first leg at Anfield on Tuesday.
“Liverpool FC can confirm Alex Oxlade-Chamberlain’s 2017-18 season is over for both club and country due to a knee ligament injury sustained against AS Roma on Tuesday evening,” Liverpool stated on their official website.
“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 finals in Russia with England.
“The 24-year-old was assessed by the club’s medical team at Melwood on Wednesday morning and no specific timescale is being placed upon his return to action at this stage.
“However, 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.”
Oxlade-Chamberlain joined Liverpool from Arsenal this season and has excelled after a slow start.