Ireland centre Robbie Henshaw (29) will miss their match against Australia in Dublin on Saturday due to a niggling hamstring injury, the Irish Rugby Football Union (IRFU) said on Monday.
He missed the 19-16 win over South Africa but returned for the 35-17 victory over Fiji in which he suffered a recurrence of the injury.
"Robbie Henshaw's hamstring issue will rule him out of this week's game...he will continue his rehab at Leinster," the IRFU said in a statement.
"The players who picked up knocks against South Africa - Johnny Sexton, James Ryan, Andrew Porter, Josh van der Flier and Hugo Keenan - will be monitored across the early part of the week and re-integrated into training according to their individual management plans."