Ireland will continue to field a patched-up midfield when their Grand Slam bid resumes against England on Sunday but coach Eddie O'Sullivan remains confident it will test the ailing world champions.
Captain Brian O'Driscoll returns to the side after missing the one-sided victory over Scotland but Gordon D'Arcy, who has also been troubled by a hamstring injury, has been ruled out of the Lansdowne Road showdown.
D'Arcy missed the trip to Murrayfield as well but rejoined his Ireland team-mates at the start of the week after receiving intensive treatment at a rehabilitation centre in Spala, Poland.
However, the Leinster midfielder suffered a setback during training on Tuesday and was withdrawn from the session, with O'Sullivan confirming he has no chance of facing Andy Robinson's side.
"Gordon hasn't made it because his hamstring isn't quite right. He has not been comfortable on it in training so there is no point risking him," said O'Sullivan.
"The injury is going to take more time than we thought to heal, although there is nothing sinister in it. But Brian is good to go after completing two full training sessions - there hasn't been any reaction to his injury.
"We will look at him again but at the moment all the signs are pointing to the fact he will be OK for the weekend. But you never know with these things."
D'Arcy's loss is a big blow as Ireland hoped to have all their big guns available against England, who are reeling from an appalling run of eight defeats from their last 11 Tests.
But his absence allows Shane Horgan to deputise once again - a task the Leinster back has accomplished with considerable aplomb in the past, not least against South Africa and Argentina during the November internationals.
Horgan's power can cause opposition midfielders a major headache and O'Sullivan is happy with his centre pairing for Sunday - and revealed the reasoning behind his decision not to give Kevin Maggs a chance.
He said: "Once we knew Gordon wasn't going to make it we went back to the formation we had in the autumn with Shane playing at 12 and Kevin moving to the bench.
"It worked well so it wasn't a difficult decision.
"I think Shane and Brian are a better combination than Kevin and Brian. Shane did a really good job against South Africa and Argentina. We can call on Kevin as an impact player. The decision is consistent with our recent selections."
The only remaining question mark for Sunday's Dublin showdown lingered over who would take the number seven jersey - Wasps' Johnny O'Connor or Munster's Denis Leamy.
But the decision was taken out of O'Sullivan's hands when Leamy - who lost his place to O'Connor against Scotland - suffered a hamstring injury while on Celtic League duty last weekend.
"Denis wasn't available, so that narrowed the options down. Johnny did play well against Scotland and he knows the English team because he faces their players on a weekly basis," he said.
"Sunday will be a good game for him to play in. The back row is not a done deal but Johnny has done a good job at openside."
O'Driscoll will be skipper for the clash but Munster fly-half Ronan O'Gara will lead the team out to mark his 50th Ireland appearance.
Ireland team to play England in the RBS 6 Nations at Lansdowne Road on Sunday:
G Murphy (Leicester); G Dempsey (Leinster), B O'Driscoll (Leinster, capt), S Horgan (Leinster), D Hickie (Leinster); R O'Gara (Munster), P Stringer (Munster); R Corrigan (Leinster), S Byrne (Leinster), J Hayes (Munster), M O'Kelly (Leinster), P O'Connell (Munster), S Easterby (Llanelli), J O'Connor (Wasps), A Foley (Munster).
Replacements: F Sheahan (Munster), M Horan (Munster), D O'Callaghan (Munster), E Miller (Leinster), G Easterby (Leinster), D Humphreys (Ulster), K Maggs (Ulster).
England flanker James Haskell insists he will be pushing as hard as possible to be back from a toe injury in time to make his case for a spot in Eddie Jones' side looking to defend their RBS 6 Nations title next year.