Gordon D'Arcy and Keith Earls are Ireland's biggest injury concerns for Sunday's RBS 6 Nations clash with England at Aviva Stadium.
Team manager Mick Kearney insists the Irish are "guarded" over the duo's chances of participating after D'Arcy suffered a dead leg and Earls incurred a shoulder problem during Saturday's 30-22 victory over Wales.
"Gordon suffered a nasty dead leg but is recovering better than we expected," Kearney said.
"The prognosis is still guarded but we are more hopeful than we were yesterday. He will do modified training today and tomorrow.
"Keith took a blow to his left shoulder that was quite sore. The prognosis is guarded.
"He will do modified training today and tomorrow and will be reviewed by a specialist tomorrow."
"Peter took a bang to the head in a tackle and is being treated as concussion. He was fine after the game and was well today," Kearney said. "He'll follow the IRB return to playing guidelines and it depends on how he recovers during the week."
Brian O'Driscoll and Mike Ross played a full part in training after suffering a head wound and severe cramp respectively against Wales, while Rob Kearney is available for Sunday despite his bruised back.
Connacht full-back Robbie Henshaw, Leinster back-row Rhys Ruddock, Ulster centre Darren Cave and Ulster wing Andrew Trimble have been called up as cover.