Kane is expected to be the subject of a bid from the Spanish giants as they look for a replacement for Karim Benzema, who is set to move to Saudi Arabia.
The striker is fresh from another 30-goal season in the Premier League but could still prevent Spurs from finishing eighth, their worst league finish in 15 years.
Kane has just one year remaining on his contract and Spurs insist their talisman is not for sale and will be part of new manager Ange Postecoglou’s first-team squad next season.
But Porro, speaking at a press conference in Spain, insists Kane would go with his and his team-mates’ blessing.
“If Kane decides to go to Real Madrid we’ll be as happy as he is or more,” he reportedly said at the opening of a training camp named after him.
Porro joined Spurs in January, initially on loan ahead of making a permanent switch from Sporting for around £40million, and struggled in his first few weeks.
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But a move further forward into the attack has benefitted the player, who says he is “very happy” at the club despite the season having “not gone so well”.
He continued: “It’s another country, another language and you have to adapt quickly, but I’m happy and I hope that next season we start well,” he said.