Ruben Loftus-Cheek has returned to Chelsea for treatment on the ankle injury he sustained just after Christmas, with Crystal Palace unsure when the England midfielder will be able to resume his loan spell at Selhurst Park and his participation in the summer’s World Cup in doubt.

Loftus-Cheek hobbled out of Palace’s 3-2 home defeat by Arsenal on 28 December and, despite the problem appearing innocuous, the joint has failed to respond to rest. The club’s medical staff spoke with their counterparts at Chelsea to discuss how best to proceed and the 22-year-old’s parent club determined he should be monitored for a further three weeks.

If the ankle fails to improve in that time, they will explore surgical options but in the meantime Loftus-Cheek is back under the champions’ supervision.

“Chelsea insist on having him back there on this period of rehabilitation, so we won’t really know until such time that they release him back to us,” Roy Hodgson said. “The agreement was that he would spend two to three weeks without having any surgical intervention, in the hope that the problem he has will be resolved naturally.

“During that time Chelsea have insisted they take care of that because they regard him as their player. We will now wait for that period to pass, then he’ll come back to us. We will then test whether or not the injury is still there or whether, as they think, the injury has cleared up. So there’s another 10-14 days to go before I can tell you anything about Ruben Loftus-Cheek at all. I haven’t seen him literally for 10 days.”

The Lewisham-born midfielder has made 15 Premier League starts for Palace this season and impressed enough to earn his first two senior England caps in November’s friendlies against Germany and Brazil. The injury casts serious doubt on his participation in March’s internationals against the Netherlands and Italy and, given the increased competition among Gareth Southgate’s midfield options, his involvement at the World Cup.

Loftus-Cheek is one of two domestic loans at Palace, alongside Manchester United’s Timothy Fosu-Mensah, and his early release back to Chelsea would free up one slot before Wednesday’s transfer deadline. Yet Palace are not inclined to terminate the loan. “We do not have anybody lined up we want to loan that would even encourage us to send Ruben Loftus-Cheek back,” Hodgson said. “Second we still think he might recover from this injury quicker than has initially been suggested. We want him with us at an important time of the season to help us win games to help us stay in the league.

“So there has not been a question of us sending him back. The questions have been around the treatment and where the treatment should take place. That is something that goes on between the medical departments and is bound by the contract we signed with Chelsea.”

Palace, who play West Ham United on Tuesday night, still hope to bring in up to three players before the transfer cut-off. Their under-used South Korea international, Lee Chung-yong, is expected to rejoin Bolton Wanderers on loan after the game at the London Stadium.