Ulster flanker Neil McMillan has been called into the Ireland squad ahead of Saturday's showdown with Wales as cover for David Wallace.
Wallace is still recovering from the thigh strain he suffered last week and missed training yesterday as a result of the injury.
Coach Eddie O'Sullivan, who is due to name his side for Sunday's clash at Lansdowne Road tomorrow, is closely monitoring the fitness of Shane Horgan, John Hayes and Keith Gleeson who picked up knocks in Paris last weekend.
Ireland captain Brian O'Driscoll is still hoping to be fit although a decision on his inclusion is unlikely to be taken until the last minute.
England have delayed naming their side to meet Scotland on Saturday for a further 24 hours because of injury concerns about captain Lawrence Dallaglio and centre Jason Robinson.
Both players sustained hand injuries in the world champions' 50-9 win over Italy on Sunday in their opening match of the tournament.
Coach Clive Woodward, who had already postponed his team announcement by a day, is also waiting to hear the result of a disciplinary hearing into an incident involving replacement lock Steve Borthwick.
Borthwick, who was cited for foul play in a club match, was dropped from the bench for the Italy match. His place was taken by Simon Shaw.