Ulster and Ireland forward Iain Henderson out for up to three months
Ulster and Ireland forward Iain Henderson has been ruled out for a minimum of 10 weeks after undergoing surgery on a thumb injury on Monday.
The 26-year-old will miss most of Ireland's Six Nations campaign, plus Ulster's final two Champions Cup Pool Four games, and several Pro14 matches.
In-form Henderson scored two tries in Ulster's win over Scarlets on Friday.
The British and Irish Lion is understood to want the injury cleared up before next year's World Cup.
The second row, who can also operate as a flanker, looks certain to miss Ireland's Six Nations games at home to England on 2 February, and away to Scotland and Italy on 9 and 24 February.
Henderson could be available to coach Joe Schmidt for the closing fixtures in March against France in Dublin and Wales in Cardiff.
Ulster Rugby confirmed that Henderson had surgery to "repair a torn ligament in his thumb".
Meanwhile back-row forward Matthew Rea sustained a thumb fracture playing for his club Ballymena on Saturday and also had surgery on Monday.
He is expected to be sidelined for 8 to 10 weeks.