Ireland's walking wounded gave Joe Schmidt an unwelcome headache to add to the heartache of a 10-9 defeat to France in Paris.
France swung a bruising encounter their way thanks to Maxime Medard's second-half try, but yet more injuries to an already stretched squad rubbed salt into the visitors' wounds.
Sean O'Brien, Johnny Sexton, Mike McCarthy and Jared Payne all picked up knocks at Stade de France, and with Simon Zebo and Keith Earls not fit enough to travel - added to longer-term absentees Tommy Bowe, Iain Henderson, Luke Fitzgerald, Peter O’Mahony, Mike Ross, Cian Healy and Chris Henry - Schmidt's resources are being tested to the limit.
"With Sean [O'Brien], it looks like a hamstring injury. We feared it was a knee injury, the way he planted and turned. But it looks like an upper hamstring," the New Zealander said.
"It's always a loss when you lose him because of his high work-rate and power. We're just going to have to assess him over the next 24 or 48 hours.
"Johnny [Sexton], he was pretty knocked around at the end of the game.
"Mike McCarthy certainly appeared to suffer a concussion but I've not had chance to speak to the medical team yet.
"Jared Payne played on with a dead leg for about 30 minutes. I thought he was outstanding given that context. I'm hoping everybody else will be OK for two weeks' time."
Ireland at least have the respite of a two-week break before their third RBS 6 Nations game, the daunting trip to Twickenham to face Eddie Jones' England.
