Kane was substituted in the 34th minute of his side's Premier League win over Bournemouth at the weekend, after suffering a heavy blow on his ankle from Asmir Begovic as he turned home Christian Eriksen's cross from an offside position.
Spurs were behind to Junior Stanislas' early opener when Kane went off, but Pochettino's side sprung into life after the departure of their leading scorer.
"I am concerned. Until tomorrow we can't say any more," Spurs manager Mauricio Pochettino said. "We hope it's not a massive issue for him and hope he is available for the team as soon as possible."