The Tottenham Hotspur striker topped the Premier League scoring charts with 25 goals last season, as well as netting five times in 14 international appearances, but was short of his best during the group stages of Euro 2016.
He started as Roy Hodgson’s first-choice centre-forward against Russia but made way at half-time against Wales and was not seen until the 76th minute against Slovakia.
That was his 63rd appearance since the start of 2015-16, while this is the second summer in a row where he has played tournament football following the European Under-21 Championship in the Czech Republic.
But the 22-year-old insists he is ready to return if needed in Nice on Monday evening.
“I’m not tired,” he said.
“I’ve had it before, a lot of people spoke last year when it was the Under-21s at the Euros. People said the same things then.
“But I feel 100 per cent fresh, I feel sharp, I feel ready, so if called upon I’ll be going out there and giving 110 per cent.”
Kane is vying with Sheffield-born Jamie Vardy and Daniel Sturridge, who both scored as substitutes against Wales, for a place in the starting XI, with Wayne Rooney now in midfield and teenager Marcus Rashford unlikely to start.
Much has been made of Hodgson’s decision to make six changes ahead of the goalless draw with Slovakia, alterations which will be largely reversed at Stade de Nice.
But Kane says the dressing room is fully attuned to the manager’s tactics.
“We have a great squad of players but not every player will be used every time,” he said.
“Everybody wants to play but certain players suit certain games, the gaffer has to think about which (players) he wants to use and anyone coming in or out of the team has taken it well.
“As players, we have to be ready when called upon. If it changes again on Monday, we’ll be ready for that.”
Should the Londoner start England’s first knock-out fixture since June, 2012, when they lost to Italy on penalties, he will shoulder responsibility for banishing the team’s growing reputation for profligacy.
UEFA tournament statistics record England as having 65 attempts on goal in their three games to date, a number that speaks well of their attacking intent but poorly of their conversion rate.
Just 15 of those have been on target, with three ending up in the net.
“We haven’t scored as many goals as we probably should have,” admitted Kane. “I don’t think it’s anxiety. We are doing all we can to put the ball in the back of the net and we’ve scored a few... it’s not like we’ve scored no goals at all.
“But I think we need to be a bit more clinical in the final third, not just finishing but a few crosses and passes could have been a little bit better, too.
“I think there are things we can improve on, we are trying to rectify that and we’re working hard as a team.”
While Iceland represent an easier opponent on paper than Portugal, and are 26 places lower in the FIFA rankings, they are likely to present another defence-minded opponent.
Hodgson suggested last week the public may not see the best of his side until they were involved in a more open game, but Kane backed his colleagues to find a way through.
“That’s something we are going to have to deal with,” he continued.
“I think a lot of teams will see how we play, the players we’ve got and try to defend to the best of their ability.
“The better you are the more teams are going to drop off and make it harder for you.
“We have to be aware of that and find a way to break through it. Looking at Iceland in their group games, that’s what they do and try to hit on the counter-attack.
“But if you want to progress in this tournament and go far, you have to find a solution to deal with that.”
More Euro 2016 last-16 build-up: Pages 2 & 3