DUBLIN : Ireland flyhalf Johnny Sexton will miss the Six Nations leader's trip to Italy this weekend, the Irish Rugby Football Union (IRFU) said on Wednesday, with lock James Ryan named as captain for the game.The loss of Sexton, who suffered a leg injury in the 32-19 win over France last time out, will likely open the door for fellow Leinster outhalf Ross Byrne to make just his third start for Ireland and first in the Six Nations.While the more experienced Munster number 10 Joey Carbery was recalled by coach Andy Farrell as cover earlier this week, Byrne has impressed off the bench in Ireland's last three games.Ryan's choice as captain may also mean that Peter O'Mahony, who has led his country on 10 occasions, is set to be rested on Saturday with the likes of Jack Conan and Gavin Coombes vying for a first start of the campaign.