Ireland captain Caelan Doris will be sidelined for up to six months after undergoing shoulder surgery. Doris was previously considered to be a certain pick by Andy Farrell for the forthcoming British and Irish Lions tour to Australia this summer, thought to be an almost definite Test starter at number eight and also in a two-man race for the captaincy along with England counterpart Maro Itoje. However, the 27-year-old’s Lions hopes were thrown into question just five days before the official squad announcement last week when he was forced out of club side Leinster’s shock 37-34 home Champions Cup semi-final defeat by Northampton in Dublin with a shoulder injury. Uncertainty then briefly reigned over Doris’ status for Australia, before reports surfaced that he needed an operation and would miss the entire 10-match tour having been ruled out for several months. Doris was as expected omitted from the Lions squad named by head coach Farrell at the O2 Arena last Thursday, with Itoje handed the captaincy and Ireland and Leinster team-mate Jack Conan now the clear favourite to start the three-Test series against the Wallabies at number eight, pending any further additions. Official confirmation of Doris’ layoff has now come from Leinster, who revealed that their influential skipper could be sidelined for six months as they provided a new injury update ahead of Saturday’s United Rugby Championship (URC) game against Glasgow Warriors at the Aviva Stadium. Such an update included the latest on lock James Ryan, who was among 15 Irish players named in an initial 38-man Lions squad after returning from a calf issue. “James Ryan came through the game at the weekend with no issues after his return from injury,” said Leinster head coach Leo Cullen. “James Culhane will be further assessed this week for an arm injury before a final decision will be made. “Caelan Doris had a procedure on Friday last week for a shoulder injury which will keep him out of action for between four to six months. There are no new updates on Jordan Larmour, Will Connors and Brian Deeny.”