The 29-year-old provided two assists in the Three Lions' 6-2 win against Iran as they opened the tournament with a bang on Monday at the Khalifa International Stadium.
Kane had England fans' hearts in mouths early in the second half when he went down gripping his right foot in pain after being caught by a poor Morteza Pouraliganji challenge.
The skipper managed to play on until the 75th minute but was seen leaving the ground with a slight limp and his right ankle lightly strapped.
The Football Association remained tight-lipped about Kane's fitness the following day, but it is understood the striker is to undergo a scan before Friday's clash with the USA.
England manager Gareth Southgate had downplayed concerns over his fitness in the press conference immediately following the Iran game.
"I think Harry's fine," the manager said of the 2018 Golden Boot winner.
"I mean, it obviously looked a bad tackle but he carried on in the game and we took him off, really, because we felt it was a moment we could do that."
Kane seemed fined straight after the match when he spoke to reporters, saying he was happy for others to get in on the goal-scoring act, having failed to net against Iran.
Asked if he was happy the team were not reliant on his goals, he replied: "Absolutely - to go far in any major tournament you need goals, not just from your main striker, but from all over the place.
"We started the game really well, the boys who have come on have done fantastic. Really pleased and I know it'll give everyone confidence.
"Everyone, whenever you score or get an assist, it lifts their spirits and we're going to need everyone to do well in this tournament."
Kane will be hoping to have escaped injury as the free-scoring frontman chases down Wayne Rooney's record England goal haul of 53, of which he is just two shy.
But, like Southgate, he was unhappy that England allowed Iran to score twice on Monday.
"To score six goals in a World Cup match is pretty good, really happy, but disappointed to concede a couple of goals but overall a great start to the tournament," he added.