Lewin was carried away on a stretcher after fracturing and dislocating his ankle while celebrating Daniel Sturridge's equaliser during the 2-1 defeat to Italy on Saturday.
"That was a very sad moment for us," England boss Roy Hodgson said. "In celebrating the goal he jumped up, landed on a water bottle and dislocated his ankle.
"It was very painful. He was taken to hospital. The doctor set it, put it back in at the side of the field, but it's the end of the World Cup for Gary."
The 50-year-old Londoner was brought into the national side by Glenn Hoddle in the late 90s, and became the Three Lions' full-time physio in 2008, having previously managed the role with his obligations as Arsenal's physiotherapist.