Ireland coach Eddie O'Sullivan has said he is "very worried" about the fitness of Shane Horgan who injured a knee in a World Cup warm-up defeat by Scotland.
Shane Horgan is doubtful for the Rugby World Cup
"Shane was a replacement but twisted his knee in the warm-up and Andrew Trimble came in," said O'Sullivan.
"Shane will have a scan in the morning to assess the extent of the damage.
"Brian O'Driscoll came off with a tight hamstring and a sore wrist and other players took knocks. I have some tough decisions before naming my squad."
The Ireland coach said that a below-par first-half display cost his side dear in the 31-21 loss to the Scots at Murrayfield.
"We did not defend as well as we would like and we conceded some poor tries while our set-piece creaked early on, although it got better as the match went on.
"It was not a day for the wingers but the back five had plenty to do in a bit of trench warfare.
"In the first half, we tried to play too left to right instead of up the middle but in the end we could have won against a strong Scotland side.
"This was a good test of what we want to do and where we want to go and I will take time over my selection," added O'Sullivan.
The Ireland squad is due to be named at 1100 BST on Sunday morning.