Saracens lock Maro Itoje could make his first England start after Joe Launchbury was ruled out of Saturday's Six Nations clash against Ireland with a hamstring problem.

England effectively passed Launchbury fit on Wednesday morning, forwards coach Steve Borthwick declaring the Wasps second row's hamstring issue was "no concern".

But by late Wednesday 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 on Wednesday 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."