Sam Underhill told to be a defensive leader on second England cap

• ‘What I expect from Sam is a dominant performance,’ says defence coach• Underhill gets chance to build on fine club form and promising England debutSam Underhill has been challenged to produce a “dominant performance” for England against Argentina on Saturday, having been appointed one of Eddie Jones’s two leaders of a defence tasked with establishing itself as the best in the world.Underhill wins only his second cap but has excelled for Bath this season, averaging 15 tackles per match, and has the chance to cement himself as England’s first-choice openside flanker with Tom Curry out until F…