Leinster coach Michael Cheika has been forced to plan without scrumhalf Chris Whitaker and Girvan Dempsey as he prepares for Friday's Magner's League match against the Ospreys at the Liberty Stadium.
The Australian fractured his leg in the heavy defeat to Toulouse last weekend and is expected to be out for up to 10 weeks.
Ireland fullback Dempsey also suffered a leg injury but it is unclear how long he will be out of action for, though an update is expected later in the week.
Gordon D'Arcy's hip injury is also a concern but the Ireland centre is included in the 26-man squad among nine other internationals.
Whitaker's absence means a place for Ireland Under-20 Grand Slam winning scrumhalf Paul O'Donohoe, who will vie for a place with Cillian Willis and Chris Keane. The latter has just returned after injury.
Prop Cian Healy, O'Donohoe's Belvedere schoolmate, is also included.
Cheika is keen to get back to winning ways after he saw his side humbled in Ernest Wallon Stadium on Sunday evening.
"It would have been our intention to freshen things up this week with the five-day turnaround from the Toulouse game on the Sunday to another big challenge against the Ospreys on the Friday night," said the Australian today.
"The Ospreys are a very strong side and the last two matches that we have had over there have been tight affairs. In year one we lost in the last minute and then in year two, the game went down to the last few minutes.
They lost on that occasion as well and this time Cheika is hoping for more "composure" and for his charges "to play a bit smarter".
"The Ospreys have a brilliant squad. They have great depth and even though they are likely to be without some of their Welsh internationals for this game, they have great experience in the likes of Marty Holah, Justin Marshall and Filo Tiatia.
"The 7, 8, 9 and 10 axis is very strong and with the likes of Nikki Walker out wide and Ian Gough, they have experience throughout the squad."
Injuries, says Cheika, are "part and parcel of the game" and he insists that his side are not downbeat ahead of their seventh Magner's League outing of the season.
"It's not like we're in a losing streak. Our last two performances in the Magners League before the win against Leicester had been good, away to Ulster and then at home to Connacht.
"We're in third place in the league and we want to be as competitive as we possibly can be.
"This year I'm much happier with the squad's ability to rotate and we will need to be at our best on Friday," added Cheika, who will announce his team on Thursday afternoon.
Leinster squad to face Ospreys
Forwards: Cian Healy, Ollie le Roux, Brian Blaney, Bernard Jackman, Juan Gomez, Stan Wright, Leo Cullen, Cameron Jowitt, Malcolm O'Kelly, Devin Toner, Keith Gleeson, Shane Jennings, Kevin McLaughlin
Backs: Chris Keane, Paul O'Donohoe, Cillian Willis, Felipe Contepomi, Jonathan Sexton, Christian Warner, Rob Kearney, Michael Berne, Gordon D'Arcy, Brian O'Driscoll, Gary Brown, Shane Horgan, Luke Fitzgerald
