Saracens lock Maro Itoje could make his first England start after Joe Launchbury was ruled out of Saturday's RBS 6 Nations clash against Ireland with a hamstring problem.
England effectively passed Launchbury fit yesterday morning, forwards coach Steve Borthwick declaring the Wasps second row's hamstring issue was "no concern".
But by late yesterday afternoon, the Rugby Football Union had issued a statement to confirm Launchbury had been forced to admit defeat in his battle to face the Irish.
Lock Courtney Lawes was hurriedly drafted back into England's 23-man match squad, just a day after being released back for club duty with Northampton.
"It was anticipated that Launchbury would take part in England's third game of the tournament but after further consultation with team medical staff it has been decided he is unfit to play," the RFU confirmed in a statement.
"The lock will now return back to his club (Wasps) for further treatment on a hamstring injury."
England's statement confirming Launchbury's revised injury assessment came just hours after forwards coach Borthwick had insisted the 24-year-old would have no issues making the fitness grade for the weekend.
"He's good, no concerns for the weekend," said Borthwick of Launchbury, late yesterday morning.
"Yesterday he had a little bang but no cause for concern for Saturday.
"It was just a tight hamstring, but he's no concern."
Launchbury's loss could prove highly-promising lock Itoje's gain, with the 21-year-old now likely to be promoted to the starting line-up from the bench.
Itoje made his Test debut off the bench in England's 40-9 victory over Italy in Rome, impressing in a second-half cameo.
Eddie Jones has been at pains not to rush rookies like Itoje as he gets to grips with his new role as England boss, but has already tipped Saracens' astute and gritty lock to win in the region of 60 caps.
Forwards coach Borthwick believes England boast impressive depth in the second-row department.
"I think it's a competitive position right now, and that's a good thing," Borthwick said of England's second-row area before Launchbury was forced to drop out of the squad.
"We've got a mixture of players there with different levels of experience.
"That's a really good thing for the squad to make that a competitive area.
"With that it spurs the intensity of training.
"Eddie will finalise the selections for the squad and team that we think can win the game this weekend."
Meanwhile, Mike Brown has fully endorsed boss Jones' assessment that England do not boast any world-class players.
Brown lamented England's lack of global stars following the abysmal World Cup performance in the autumn - and four months on the Harlequins full-back believes "there is no change" in that regard.
England will head into the Ireland clash with Jones' candid words ringing in their ears, but Brown insisted the former Australia head coach was right not to pull any punches.
"As a player you just want people to be honest," said Brown.
"You want to know what you need to work on.
"We all want to be the best players we can be and if we want to be the best team in the world we need world-class players.
"It's about being honest and we welcome that as players.
"I said it (that England had no world-class players) at the end of the World Cup, and there is no change.
"We've only been together four weeks (under Eddie Jones), so my view hasn't changed on that.
"Eddie is the boss, and he said it and that's what counts.
"He has challenged us and now we need to go away and make ourselves world-class players.
"If what Eddie has said has a negative impact on you, you won't be in the squad for very long."