Harry Kane may have to leave Tottenham to reward world-class talent

Apparently, Harry Kane has to prove himself. Shortly after scoring twice in Tottenham's 3-1 win over Borussia Dortmund on Wednesday, talk turned to what he has to do in order to prove he's world class.

"He could have to leave Spurs to become that top, top world class Robert Lewandowski-type player," said Phil Neville, commentating for BBC Radio. "If Spurs maintain being a top-four team, that will not be good enough.

"I think he needs to be challenging for the Ballon d'Or. I think he needs to be challenging for the Champions League and if Spurs are always going to be that 'nearly team,' eventually he will want to leave and join a Real Madrid or a Barcelona. There will always be a doubt about Harry Kane until he gets to that level."

It's perfectly possible Kane will one day leave Tottenham -- but not in order to prove his quality. In fact, it's a little curious to think he needs to do anything in order to do this. His goals against Dortmund were his 102nd and 103rd for Spurs, scored in his 170th game. Gareth Southgate said recently that Spain coach Julen Lopetegui expressed his jealousy about working with Kane. He's seemingly spent his entire career facing questions about his quality, before casually punching through them like they're wet paper, purely with the weight of goals.

The beauty of Kane's game is in its simplicity. He is perhaps the purest exponent of the simple things among any striker playing today, which includes thinking about the most straightforward way of scoring a goal. When he does a Cruyff turn, or a shimmy, it's not to show off but because his brain has calculated, very quickly, that it's the easiest way to the net.

That's perhaps why he's so willing to use his left foot. Both goals against Dortmund were scored with his "weaker" foot, but the second in particular provided an example of how his mind works. Receiving the ball on the left side of the area in space, most right-footed strikers would have cut inside to shift the ball to their strongest boot, but that would have allowed the defence more time to block his path to goal, and cut down his shooting options.

Kane calculated he could save time and maximise his chances of scoring by simply shooting with his left, which he did, sending the ball into the corner of the net. It's astoundingly simple, and you wonder why more strikers don't do it. If only because it makes Kane even more difficult to defend against: defenders are trained to push forwards on to their weaker side, but if they know that Kane is more or less just as likely to get a decent shot in anyway, their options are limited. All of which should serve as more evidence the debate about Kane's place among the best strikers in the world is moot by now.

But the question of whether he will one day outgrow Tottenham is another matter.

Kyle Walker's departure for Manchester City in the summer should not be seen as an outlier, an individual player agitating for more money and greater chances of silverware. Rather, he is probably the first of this brilliantly talented generation of Spurs players to realise there is more beyond the rapidly increasing walls of the new White Hart Lane.

At the moment, Kane is young enough to be content. He is 24, theoretically not yet in his prime, and can live with not earning quite as much as he could elsewhere. He can be patient with the idea that he's playing in a growing team, in a comfortable environment, under a manager who understands him and can get the best from him.

But how long will that last? Money and trophies will take over from basic contentment after a while. Even though he is handsomely remunerated, he could earn double, maybe triple elsewhere. This is a brilliant Tottenham team, but they haven't achieved anything yet. Two title challenges, a cup semifinal and a couple of Champions League campaigns are great for now, but is it enough?

It wasn't for Walker and if his comments earlier in the summer are anything to go by it won't be for Danny Rose either. And reports this week suggest Dele Alli, having left his agent of nearly a decade, is being courted by Mino Raiola and Jorge Mendes -- not men who typically advise their clients to sit tight and be happy with underpaid progress.

Kane has enough time to stick with Tottenham for a while, and the hope will be they will win something in that time. And perhaps they will.

He may have to move at some point -- but in order to reward his talent, not fulfil it.