LONDON, June 18 (Reuters) - Harry Kane is England"s captain, chief goalscorer and talisman, which is great when things are going well, but when the striker is off the boil, as he was horribly again on Friday against Scotland, his sluggishness seems to permeate the whole team. England were desperately short of ideas, invention and energy, managing a solitary shot on goal in a 0-0 draw that was a just reward for a Scottish team who were the exact opposite, making up easily for a supposed gulf in class with their commitment and organisation. On Sunday, Kane was taken off late in the 1-0 win over Croatia, looking out on his feet, with some suggesting the hot conditions may have played a part in his sluggish display. On Friday, on a wet, cool night he looked even worse and was hooked after 73 minutes of largely purposeless toil. In the first half he sat deep, as has become his more normal position for his club Tottenham Hotspur, but was unable to find a way to influence the game either in collecting the ball or moving it forward. Kane pushed up more after the break but was handled with ease by Scotland"s central defenders. There can be few players whose standards swing so dramatically, seemingly dependent on their fitness. As England were bundled out of Euro 2016 by Iceland, Kane played as if he was carrying a bag of cement on his back. Two years later he was the leading scorer at the World Cup, his goals and all-powerful front-running display driving England to the semi-finals. Back on home soil, however, he again looks slow and on Friday he was unable to bring his influence to bear in any way. JADED KANE Pundit Graeme Souness said Kane looked "a shadow of the player we know he is. He looks leggy, he doesn"t look himself, he looks jaded... he needs to wake up." Manager Gareth Southgate replaced him with Marcus Rashford, having also thrown on Jack Grealish after an hour, but they were the only changes he made despite the team seemingly desperately needing a shake up. England managed one shot on target all night - a decent effort by Mason Mount - and though John Stones hit a post with an early header, they rarely otherwise looked like unlocking an impressive Scotland defence. Far too many players took the easy, safe option and, though England were right to try to dampen the frenetic early exchanges as the fired-up Scots tore into them, they failed miserably to use their increased possession to do anything more than spray the ball laterally. The result is no disaster for England, who have four points in the bag ahead of their final game against Group D leaders the Czech Republic on Tuesday, but the performance should worry Southgate. He is not a man to panic but, as he has become more established in his position, that calmness has too often developed into a conservatism that has left fans and pundits scratching their heads. Unless Kane is carrying an injury he is almost certain to lead the line against the Czechs, and beyond, but if England are to have any chance of going deep into the tournament, their number nine will need to rediscover that lost verve, or make way for someone who still has it.