England striker Kane was forced off early on in Sunday’s 6-0 FA Cup quarter-final win over Millwall after rolling his right ankle in a challenge with defender Jake Cooper.
The swelling has reduced enough for him to have the joint scanned on Tuesday, and both player and club are now sweating on the results.
They are facing an anxious wait to get a better idea of the seriousness of the setback, and Spurs’ main goal-threat may require a second scan before a specialist can put a timescale on his recovery.
Kane, 23, damaged ligaments in the same ankle earlier in the season against Sunderland and was out for seven weeks, missing 10 matches.
Tottenham are keeping their fingers crossed for good news and that this recurrence is not quite as serious, which would allow Kane to return in four to six weeks’ time.
That would see him back by the middle of April — in time to be available for Spurs’ FA Cup semi-final against Chelsea and the north London derby against Arsenal a week later, as Spurs scrap for a top four finish.
But if the setback is worse, Kane could be looking at a lay-off of around two months, which would rule him out until early May.