Josh van der Flier needs to emerge as Sean O’Brien’s successor in the Six Nations

When All Blacks captain Richie McCaw announced that he would be retiring after the 2015 Rugby World Cup, New Zealand Rugby had a problem.

The All Blacks were about to lose their best player, their unquestioned leader, one of their most marketable assets, and quite possibly the best player to ever lace up a pair of boots, but, as predicted, New Zealand had an abundance of options to replace their leader-in-chief when he finally bowed out. The Hurricanes' Ardie Savea, the Chiefs' Sam Cane and the Crusaders' Matt Todd all emerged as viable candidates to succeed McCaw, but it was ultimately Cane who emerged as his heir apparent. But Cane had 31 games of international rugby next to his name when he received his opportunity to start without the presence of McCaw. 1456 days had passed after he made his international debut against Ireland in 2012. He had effectively spent spent four years sitting, waiting for the best player, or at least the best forward in the country's history to go. Josh van der Flier is not Sam Cane, he has just nine caps to his name, and Ireland flanker Sean O'Brien is not at the same stage of his career as Richie McCaw was heading into the 2015 Rugby Wold Cup, but, while O'Brien may only be 30, van der Flier has an opportunity to emerge in this year's Six Nations as the Tullow Tank's long-term successor. I'm not saying O'Brien is in anyway near finished, far from it, but he does have an extended injury profile, and when guys like Luke Fitzgerald and Stephen Ferris are retiring in their late twenties, it is a possibility that you have to consider. However, since making his Ireland debut in the 2016 Six Nations, van der Flier's international career has been a stuttering episode of marvellous highs followed by injury induced lows. The Leinster openside was ruled out for the majority of the 2017 Six Nations with a grade three injury to his AC joint, while he missed the 2017 November internationals later that year with syndesmosis. van der Flier was one of the stars of Ireland's 2016 November series, and after an injury plagued 2017, he needs to use this year's Six Nations to leave no doubt in Joe Schmidt's mind as to which player deputises in the absence of O'Brien. https://twitter.com/SportsJOEdotie/status/958702405427843075 Our Twitter poll on Wednesday indicated that the SportsJOE audience rates van der Flier significantly higher than his Leinster teammates, but we're not sure if Ireland head coach Joe Schmidt sees the competition in a similar lens, as he has favoured Murphy in the past. Murphy has been playing well this season for Leinster but he's made less tackles than van der Flier and has won less than half as many turnovers in nearly just as many minutes as the Wicklow born openside. With the likes of CJ Stander, Cian Healy, Tadhg Furlong, James Ryan, Iain Henderson, Bundee Aki and Robbie Henshaw all likely to start on Saturday, Ireland have no shortage of ball carriers, and while van der Flier has proven to be both deceptively quick and deceptively powerful with ball in hand, Ireland need a player like him that is strong over the ball and can get through a mountain of work defensively. The key in any backrow is balance, and while Ireland can't go wrong with any of the three options, van der Flier's defensive workrate could prove invaluable against a French team that typically tries to run the opposition off the park when they play in Paris. "They're the same but different," Jamie Heaslip told SportsJOE. "They're all class players, you could start that backrow. The depth in the backrow is encouraging but we need a really strong squad going forward, we have learned that over the years. "Josh's numbers and his work ethic is insane, Jordi has been in incredible form and Dan has been making a massive impact as well. They all have their different styles but you could pick any of them." Heaslip was never going to say who he would back for the position, the odds are stacked against him given that it's a two-against-one the next time he walks into the Leinster dressing room no matter what horse he backs, but the depth concept is interesting. When Ireland lost Sean O'Brien at the 2015 Rugby World Cup, Chris Henry replaced him in the quarter-final against Argentina. Now Henry can't get a look into the squad, and that's with Rhys Ruddock and Jamie Heaslip both out injured. Competent, good, international calibre players like Jack O'Donoghue, Tommy O'Donnell and Henry aren't even making wider squads, never mind matchday teams. The depth has increased across a number of positions, not just the backrow, but Ireland's downfall against Argentina was rooted in the fact that they could not effectively slow down the opposition's ball as Daniel Hourcade's side ran riot on a miserable afternoon for Ireland in Cardiff. van der Flier will stop ball carriers in their tracks with his tackling and he also has the ability to steal ball. As long as Sean O'Brien is still Sean O'Brien, there will always be a place for him in an Irish forward pack, but when there's a time in Irish Rugby when the Tullow Tank is not the best openside flanker in the country, Josh van der Flier needs to be waiting there with his hand raised asking questions. In this year's Six Nations he can make a start by taking a seat in the class.