Kane suffered an injury to the same ankle which caused him to miss two spells last season when he was challenged by Bournemouth goalkeeper Asmir Begovic in the 34th minute of Sunday's game at the Vitality Stadium.
Mauricio Pochettino's side went on to win the game 4-1 despite Kane's early withdrawal, with goals from Dele Alli and Serge Aurier either side of Heung-Min Son's double, but Tottenham and England now face an anxious wait for news on their star striker.
What's the initial prognosis?
Pochettino told Sky Sports reporter Greg Whelan that the injury was "in his right ankle, possibly ligaments, similar to the injury sustained against Sunderland early last season" at half-time, and he admitted his concern over the situation in his post-match interview.
"I am concerned," he told Sky Sports. "Until tomorrow and the scan we cannot say nothing more. Of course I worry about him, his ankle. We hope it is not a massive issue for him and the team. We hope as quickly as possible he can recover and be available."
What happened last season?
Kane first injured his right ankle in the final minutes of a 1-0 win over Sunderland in September last season. The 24-year-old twisted the joint after falling awkwardly at White Hart Lane, leaving the pitch on a stretcher and departing the stadium on crutches and wearing a protective boot.
The ligament damage kept him out for six weeks overall, causing him to miss five Premier League games, three Champions League group stage fixtures and two EFL Cup clashes. He returned for Tottenham's north London derby with Arsenal at the Emirates Stadium, scoring his side's equaliser from the penalty spot.
Kane injured the ankle for a second time during a 6-0 win over Millwall in the FA Cup in March. Once again, he left the stadium wearing a protective boot. The club confirmed he had suffered ligament damage again, but it was not as severe. In the end, he only missed four Premier League games overall, returning a month later for a 4-0 win over Bournemouth.
What could he miss this time?
The severity of his latest injury remains unclear but Tottenham's upcoming fixtures mean they will be all the more eager for him to avoid a lengthy absence. Their next game is against Swansea in the FA Cup - their last realistic hope of silverware this season - and after that there are tricky Premier League trips to Chelsea and Stoke before a home meeting with Manchester City.
Kane injury concerns Poch
Mauricio Pochettino admits he is worried about Harry Kane's ankle injury against Bournemouth.
For England, of course, the big concern is the World Cup, which kicks off in three months' time in Russia. It would be a big surprise if Kane's injury keeps him out for that long, but Gareth Southgate now faces the prospect of being without him for their friendlies with the Netherlands and Italy later this month.
How will Spurs cope?
If the Bournemouth game is anything to go by, Tottenham might just be okay. Son moved into the striker position after Kane's withdrawal on the south coast, scoring twice and producing a man-of-the-match performance. The South Korean has now scored seven goals in his last four appearances and 18 overall this season.
"I like him when he plays as a nine," said Sky Sports pundit Thierry Henry. "You play him on the left, you play him on the right, you play him in the middle, and he can give you something. He's starting to look like a player who can deliver a lot for Tottenham."
Pochettino lauded Son's "fantastic season" in his post-match interview, while his predecessor Tim Sherwood backed his former side to manage without their top scorer - pointing out that they still had Lucas Moura and Fernando Llorente in reserve against Bournemouth.
"He's going to be a big miss to them as he would to any team but they've got a massive squad here now," Sherwood told Sky Sports. "They can cope without him. The likes of Lucas Moura and Llorente have not even come off the bench today."
Son's goalscoring form is encouraging for Spurs and so too is their squad depth, but what do the stats say? Since the 2014/15 season - Pochettino's first in charge - Kane has started 130 out of 143 Premier League games. Spurs have a 58.5 per cent win percentage with him in the team compared to just 38.5 per cent without him.
They might need to improve that record in the weeks ahead.
Tottenham with and without Harry Kane starting since 2014/15
|With Kane||Premier League||Without Kane|
|1.9||Goals per game||1.2|
And what about England?
Southgate will need no reminding of Kane's importance to his team. The Three Lions have a 65.2 per cent win ratio in the 23 games he has started since his debut in 2015 compared to a 45.5 per cent win ratio in the 11 games he has missed.
England would need others to step up in his absence. Kane is by far the highest-scoring Englishman in the Premier League this season on 24 goals, with Raheem Sterling (15) and Jamie Vardy (14) second and third respectively.
England with and without Harry Kane starting since his debut in 2015
|With Kane||England||Without Kane|
|1.9||Goals per game||1.3|
The likes of Danny Welbeck and Daniel Sturridge have struggled in front of goal this season, but could Marcus Rashford's double in Manchester United's win over Liverpool help him rediscover his best form in the weeks ahead?
Beyond that, England's options are not exactly inspiring, with Glenn Murray the latest surprise contender for a call-up after reaching 11 Premier League goals for the campaign at Brighton. Southgate will have his fingers crossed that Kane's injury is not serious.