Sexton, Heaslip, O'Brien and Payne are fit to face Wales
Jonathan Sexton, Jamie Heaslip, Seán O'Brien and Jared Payne are all on course to make it to The Millennium Stadium in Cardiff on Saturday afternoon (KO 2.30).
Out-half Sexton (left) came through yesterday's session - there was no contact - and has practised his kicking without repercussions from a Grade-1 hamstring strain suffered against England.
Flanker O'Brien and centre Payne have completed their return-to-play protocols and were in the process of being monitored overnight to ensure there were no adverse reactions to training.
There is still the chance either, or both, could experience delayed symptoms but the Irish management are as confidence as they can be they will come through.
READ MORE: Johnny Sexton passed fit for Wales game
Number eight Jamie Heaslip looks certain to return to the back row after his vertebrae injury having taken contact towards the end of last week and trained well since.
The question now for coach Joe Schmidt is whether to opt for Leinster's Jordi Murphy or Munster's Tommy O'Donnell for impact off the bench.