That will come as a huge blow to manager Gareth Southgate, although he was at least able to comfort himself with the news that strikers Tuncay Sanli and Mido could play against next weekend after tests on their respective injuries revealed no lasting damage.
Southgate told the club's official website: "We have had some more positive news this afternoon.
"Both Mido and Tuncay have gone for scans and there's no significant damage, and both have a chance of playing on Sunday.
"However, the injury to Julio looks more serious. It's the medial ligament in his knee and it looks like it will be at least two months."