Dylan Hartley may need surgery on his “grumbly” knee before the Rugby World Cup, with England head coach Eddie Jones left to “wait and see” how his co-captain reacts to treatment as he prepares to start the Six Nations without him. The 32-year-old will miss England’s opening games against defending Grand Slam champions Ireland and France after suffering a knee injury shortly before Christmas, with Jones putting the injury down to the years of wear and tear that Hartley has gone through for club and country. Yet the prospect of Hartley missing the entire Six Nations cannot yet be ruled out as the hooker must see how his knee reacts to “passive rehabilitation”, though a pessimistic Jones admitted that he might need surgery at some point in the future if the plan fails to work. Join Independent Minds For exclusive articles, events and an advertising-free read for just £5.99 €6.99 $9.99 a month Start your free trial Get the best of The Independent With an Independent Minds subscription for just £5.99 €6.99 $9.99 a month Start your free trial Get the best of The Independent Without the ads – for just £5.99 €6.99 $9.99 a month Start your free trial “It’s…