The Official Online RBS 6 Nations Store is open. The store has everything you need to get behind your team during the RBS 6 Nations, plus the store is now fully stocked with a much wider range of rugby merchandise.
O'Sullivan said: "Girvan and Geordan are both struggling at the moment.
"They are nip and tuck in terms of fitness and will be given until Thursday before we decide if they are ready.
"Geordan didn't train today. He started the game at the weekend for Leicester but had to come off.
"Girvan took part in training today. He did run but he's not there yet. Both are a doubt."
If neither player recovers in time, Rob Kearney will switch to full-back, Tommy Bowe will take the number 11 jersey and Shane Horgan will fill the vacancy on the right wing.
Ireland team for RBS 6 Nations match against Wales at Croke Park on Saturday:
G Dempsey (Leinster) or G Murphy (Leicester); T Bowe (Ulster), B O'Driscoll (Leinster, captain), A Trimble (Ulster), R Kearney (Leinster); R O'Gara (Munster), E Reddan (Wasps); M Horan (Munster), R Best (Ulster), J Hayes (Munster), D O'Callaghan (Munster), P O'Connell (Munster), D Leamy (Munster), D Wallace (Munster), J Heaslip (Leinster).
Replacements: B Jackman (Leinster), T Buckley (Munster), M O'Driscoll (Munster), S Easterby (Llanelli), P Stringer (Munster), P Wallace (Ulster), S Horgan (Leinster).