Harry Kane left White Hart Lane on crutches and will have tests on an ankle injury he picked up in Tottenham's victory over Sunderland.
The home side claimed all three points thanks to Kane's close-range finish after 59 minutes following a mistake by Sunderland centre-back Papy Djilobodji.
It was the second goal for Kane in two Premier League games, appearing to signal a return to form for the England international.
However, Kane went down in the closing stages after a sliding challenge on Djilobodji and had to be carried off the field on a stretcher.
The 23-year-old was later seen leaving stadium on crutches and wearing a protective boot on his right foot.
Spurs boss Mauricio Pochettino said Kane will undergo tests on Monday to determine the severity of the injury.
"We'll see tomorrow how is his ankle," Pochettino told Sky Sports at White Hart Lane.
"I'm happy for him, but disappointed with his injury. The image was a little bit tough, but we need to assess tomorrow. We hope it's not a big issue for us."
Spurs also lost Mousa Dembele, who was making his return from a six-game suspension, and Eric Dier, both of whom went off holding their hamstrings. But Pochettino played down the severity of their problems.
"Mousa Dembele and Eric Dier got cramps in their hamstrings," said the Argentine, whose side climbed to third place in the Premier League table.
"It's a coincidence. They will be available for the next few games."