Ulster and Ireland forward Iain Henderson is set to miss the majority of the Six Nations with a thumb injury.
Henderson will need surgery to repair a torn ligament and is expected to be sidelined for at least 10 weeks of action.
The 26-year-old will sit out most of Ireland's Six Nations campaign, plus Ulster's final two Champions Cup Pool Four games, and several Pro14 matches.
Henderson scored two tries in Ulster's PRO14 win over Scarlets on Friday.
Ulster also confirmed Matthew Rea sustained a thumb fracture playing for Ballymena RFC on Saturday and is expected to be absent for eight to 10 weeks following surgery on Monday.