Ireland forward Tadhg Beirne will miss the opening two matches of the Six Nations due to a knee injury, the Irish Rugby Football Union confirmed on Monday.
Munster's Beirne sustained the injury during the 9-7 Champions Cup victory over Exeter on Saturday.
The forward will be ruled out of Ireland's opener against England on Feb. 2 and the trip to Scotland seven days later.
Connacht lock Quinn Roux -- who captained his side during their 33-27 win over Bordeaux on Saturday -- has been called up to replace Beirne.
The IRFU also confirmed that Leinster's Adam Byrne will travel to Portugal for the squad training camp this week as cover for Munster wing Andrew Conway.
Leinster's Jack Conan will continue treatment on a shoulder injury at the club, whilst fellow teammates Rob Kearney and Jack McGrath will pick up more game time in the PRO14 against Scarlets on Friday.