The injury meant that Oxlade-Chamberlain would miss his third major international tournament for England through injury, after the midfielder was ruled out of the 2014 World Cup and the 2016 European Championships.
"It's obviously been really tough to miss out at this time of the season ... I was really enjoying my football, so for it to all come crashing down in one moment, with one tackle, it's never great," Oxlade-Chamberlain told Liverpool's website https://www.liverpoolfc.com/news/first-team/305326-alex-oxlade-chamberlain-injury-quotes.
"As a character I'm positive and I'm trying not to let myself get too down, obviously I've got a tough rehab ahead of me and moping around isn't going to get me through that!
"I must admit the first game against Tunisia was tough to watch – it's a moment when you realise what a great opportunity you're missing, but these things happen in life and I'm keeping positive."
Chamberlain also admitted that he was "devastated" to miss the Champions League final in May, where Liverpool lost to holders Real Madrid, with the former Arsenal player seen in tears on the pitch after the defeat.
England are top of Group G after winning both their opening World Cup matches, their latest victory coming in a 6-1 thumping of minnows Panama.
Manager Gareth Southgate's side face Belgium in their final group game on Thursday, with both teams already qualified for the knockout stages.
(Reporting by Aditi Prakash in Bengaluru; Editing by Alison Williams)
