England head coach Stuart Lancaster is facing a selection headache with Manu Tuilagi winning his fitness race ahead of the trip to Ireland.
The Leicester centre was injured for Saturday's 38-18 Calcutta Cup victory over Scotland and his replacement Billy Twelvetrees ran in a try on debut to stake his claim for a place in the starting XV in Dublin.
But Tuilagi was the chief architect of England's 38-21 victory over New Zealand in the autumn and is expected to displace former club-mate Twelvetrees should he manage to shake off his hamstring injury.
Lancaster said: "There are selection decisions across the field and that's one of them. Billy played well and Brad's contribution as always was positive.
"But Manu brings a unique set of skills and attributes to the game and the team, as we saw in his performance against the All Blacks.
"Genuinely, I'll wait and see how he trains tomorrow and on Wednesday before I make any decisions on the centre partnership. The reason I prefer to announce the team later in the week is that it allows me to look at the players in training and see who's up to speed and who isn't."
Elsewhere, Lancaster has called Will Fraser into the squad as injury cover for No 8 Ben Morgan, who is struggling with an ankle problem.
Saracens back row Fraser has been in impressive form with the Saxons and receives the nod from Stuart Lancaster with Morgan in a protective boot following Saturday's 38-18 victory over Scotland.
The RFU confirmed via Twitter: "Will Fraser of Saracens will join squad as cover for Morgan, Lancaster was impressed with his performances in both Saxons games.
"Lancaster says Ben Morgan's ankle is "still in a boot", likely prognosis is No.8 will struggle to make Ireland v England. Definitive news tomorrow."
James Haskell would be the most likely candidate to step into Lancaster's starting line-up having come on against the Scots at Twickenham.
Ireland have delayed the announcement of their squad with several players picking up knocks during the 30-22 win in Wales including talismanic centre Brian O'Driscoll.
Who will win between England and Ireland?