Rory Best ruled out of Springbok showdown with a calf injury
Ireland hooker Rory Best will miss Saturday's opening autumn international against South Africa because of a calf injury.
The 32-year-old Ulster hooker had been unable to play a full part in training this week and has been ruled out of the Dublin clash.
It is expected that Sean Cronin will come in at number two with Richardt Strauss on the bench.
Tight-head prop Mike Ross is expected to be available after recovering from a groin injury.
Ross, 34, had been unable to play for Leinster for a month.
The Ireland team will be announced at lunchtime on Thursday.
The fitness of Ross is of particular importance to Ireland coach Joe Schmidt with other tight-head options Marty Moore and Nathan White ruled out of the three autumn Tests because of injury.
There had been worries over the fitness of Jonny Sexton earlier this week but he is expected to be fine.
Gordon D'Arcy, Rob Kearney and Jack McGrath have all been back in full training this week at Carton House, while Ulster duoStuart Olding and Tommy Bowe have come through concussion protocols and will be available too.