Johnny Sexton can avoid more head injuries with a new tackle technique, believes Shane Horgan

Can you teach an old dog new tricks?

Johnny Sexton is Ireland's most influential player and - as long as he stays fit and firing - the key to an historic third Six Nations on the trot. His attacking and tactical play is his stock and trade but the Leinster, Ireland and Lions fly-half is a prized defensive asset and a ferocious tackler. Perhaps too ferocious. Sexton's former Leinster and Ireland team-mate Shane Horgan believes the 30 year old will be lucky to avoid another bang to the head unless he considers altering his tackling technique. Horgan was speaking on the Irish Times Second Captains podcast in the wake of the confusion surrounding Sexton's replacement early in Leinster's heavy Champions Cup defeat at Wasps on Saturday. Initially the province reported that Sexton had suffered a concussion before coach Leo Cullen moved to clarify the situation on Monday. The initial diagnosis of a fifth concussion in little over two years led George Hook to plea with the former Racing Metro playmaker to retire, and while the situation is seemingly not as grave as first reported, his former team-mate Horgan would like to see Sexton try tackle opponents at a lower point than he currently does. "I think he has to think about doing what he can without being an ineffective tackler or feeling uncomfortable in his body position," he said. "One of three things is going to happen: Johnny is going to continue on with his upright tackling style that he has always had and he is going to be lucky for the rest of his career and not have too many bangs, and no concussive bangs, and for it to not be a massive issue. "The other option is he continues on and he does take concussive bangs and he is forced to retire, or thirdly, he can opt to try and change his technique a little and limit his exposure to potential head clashes," added Horgan. Sexton's high tackling style is seen as partly responsible for the number of head knocks he has suffered, and is viewed as contrary to the approved technique now taught to young players coming through the academies. Garry Ringrose below is from the new generation that looks to tackle lower on the opponent's body. Horgan believes the problem is magnified by Sexton's position on the field, which is inhabited by lots of big, powerful ball carriers. "Because he is so brave and also the position he is in, with a lot of upright runners running directly into him, carrying the ball very chesty and often leading with their head, I think it is a very hard position to tackle effectively. Those lower tackles are more difficult. "I am not sure if it is something he is working on or not," said Horgan, who added that he did not think Saturday's clash with former team-mate Brendan Macken could be avoided. "Sometimes things just happen and there is nothing you can do about them and I do think this weekend was one of them, but if you do have any opportunity to limit severe concussive injuries you have to investigate them and it is worth working on," he said. "I would like to see Johnny Sexton play for as long as he can at the highest level and not sustain any more concussive knocks."