The injury was sustained in training this week but Curry still considered a certainty for the 33-man squad that coach Steve Borthwick is to name on Monday.
He only turned 25 in June but has already amassed 46 caps for England and three more for the British & Irish Lions.
Curry could, however, go into the tournament having missed the majority of England’s warm-up internationals. "We are very hopeful he will play this month. We don’t think it will be too long, but we will be smart with him as well," defence coach Kevin Sinfield told reporters on Friday.
England have received some good news on the injury front, though, with winger Henry Arundell returning to training after recovering from a hamstring injury.
England play the first of their warm-up games against Wales in Cardiff on Saturday, with a team largely filled with players on the fringes of World Cup selection, offering them the last chance to make an impression before Monday’s announcement.
“First and foremost, it’s a test match. I’m sure some players will have selection in the back of their minds, but we want to show how we have improved,” Sinfield said.
“It would be unfair to say it’s all on this game because it’s not. We have got to take into account the last eight weeks, how players have performed throughout the season and exactly what we need going forward.
“There are some wonderful players who will miss out, sadly, because we can’t take everybody. We will try to get to the right place with the right balance within the squad.”
England will play Wales again next Saturday, August 12th at Twickenham before their final warm-up tests against Ireland in Dublin on August 19th and Fiji at Twickenham on August 26th.