England have been dealt another World Cup injury scare after Glen Johnson was ruled out of Liverpool's Champions League pursuit for an "indefinite" period by Brendan Rodgers.

The Liverpool manager revealed the right-back needs to rest an ankle problem he has been carrying for some time, starting with the FA Cup fourth-round trip to Bournemouth on Saturday. But Johnson is also struggling with a groin injury that may require surgery in the buildup to the Brazil finals.

No decision has been taken on whether the 29-year-old needs a groin operation, with Liverpool hoping an extended rest will ease Johnson's various ailments, but the prospect will be a concern to the England manager Roy Hodgson, who has already lost Arsenal's Theo Walcott from his World Cup plans due to a cruciate ligament injury.

"Glen has played a lot of the season with injuries and really put himself out for the team, but unfortunately he is struggling with a number of injuries now," said Rodgers. "It will be indefinite really, the timeline he will be out.

"He's had a real bad ankle for a period of time and just one or two other issues that haven't allowed him to be 100%. I think everyone has seen over many years the speed, fluency and how good he's been, but for part of this season he's been restricted and that's obviously been difficult for him. He has put himself out for the team, he has trained and played, but it is just at that point now where we need to get him right. There's no timeline on it. We just need to assess it and we'll take it from there."

Injuries have taken an inevitable toll on Johnson's form in recent months but his absence represents a setback for Rodgers as he attempts to steer Liverpool back into the Champions League.

Liverpool lost the influential Lucas Leiva for up to two months last Saturday with a knee ligament injury sustained against Aston Villa, Daniel Agger has also been sidelined with a calf problem and José Enrique is "weeks away" from returning to the problematic left-back position.

Jon Flanagan, however, has returned to full training having recovered from a hamstring strain suffered before Christmas and should be fit for next Tuesday's Merseyside derby at Anfield.

"I am disappointed for Lucas because he's been very important for our squad this season," the Liverpool manager added. "It was something that was innocuous really and has put him out for a few months. Hopefully he'll get back sooner rather than later. He'd been in good form this season and had worked his way back into the Brazil squad. Knowing what he is like, he'll be back sooner rather than later – and he'll do everything in his power to get back. In the meantime, that leaves us short of a really good player."