The 23-year-old was still struggling for game time towards the end of Defoe's time at Spurs and had to endure several loan spells before finally being given an opportunity to play for the first-team regularly.
"I wasn't surprised," Defoe told Sunderland's official website when asked about Kane's form.
"I said to people even when I was there that I felt at times he should have got a chance before going out and splashing so much money on other players.
"He had to wait. He went on loan, came back and he's doing his stuff.
"When I was there he played a couple of Cup games here and there.
"But he was always someone I looked at and thought 'yeah, you'll do well - I think you'll score goals in the Premier League.'
"He was always sharp in training and didn't seem out of place. I looked at him and thought 'it's just a matter of time before you come through and score goals.'"