Ireland captain Johnny Sexton has been left out of Sunday's must-win game against Six Nations favourites France in Dublin after suffering a blow to the head against Wales last week. Fly-half Sexton failed to pass the return-to-play protocols after the incident in the 21-16 defeat in Cardiff. The skipper's long-standing half-back partner Conor Murray will also be absent. It will be the first time since the 2011 Six Nations that neither player has taken part in a match in the tournament. Ulster's Billy Burns will deputise in the number 10 jersey, while Jamison Gibson-Park has replaced Murray at scrum-half. Sexton became embroiled in a row this week with his former neurologist, who said the playmaker had suffered around 30 concussions during his career. The player queried whether Jean-Francois Chermann, who treated him when he played club rugby in France, had broken unwritten rules on patient-doctor confidentiality. Later on Wednesday, Chermann said he regretted his earlier claims. Ireland head coach Andy Farrell has given Burns a vote of confidence after the England-born Ulster fly-half failed to find touch with a penalty in the dying seconds of the Wales match. Like Sexton, James Ryan was forced off with a head injury in Cardiff and misses the match against Les Bleus. Ryan's second row partner Iain Henderson steps in to captain the side for the first time. Elsewhere, Rhys Ruddock gets his first ever Six Nations start in the backrow with Peter O'Mahony serving a suspension due to his red card against Wales. France will be bidding to win in Dublin in the Six Nations for the first time in a decade, having thumped Italy 50-10 in their opening match. "It's been challenging but every Test week represents its own challenges but we are a squad and have been since we met up," Farrell said at his pre-match press conference on Friday. "Everyone has been slotting in and out. It is always at the back of your mind the what-if scenarios but the side will be going out with full confidence, meeting a really exciting French team and we will give it our best shot." pi/jw/gj