The England captain has repeatedly been linked to Manchester City and speculation intensified when he was left out of the matchday squad that defeated the Premier League champions on Sunday.
While Kane, who returned to training last Friday after requesting Spurs allow him to leave at the end of last season, has been included in the squad for the Europa Conference League qualifier doubleheader with Pacos de Ferreira, he did not travel to Portugal on Wednesday as the club insist he continues building up his fitness.
Spurs head coach Nuno, however, remains unwavering in his support for his forward, despite Pep Guardiola reiterating his interest as City reportedly prepare to launch another bid before the end of the transfer window.
"With all my respect, maybe I'm the only one that doesn't care," the new Spurs head coach told a news conference on Wednesday. "This, you cannot control. It doesn't really matter.
"What matters is behind the doors. Harry is our player, joining the group. We don't really pay much attention to what's been said outside.
"He's one of the best players in the world and we're lucky to have him."
Son Heung-Min's second-half finish proved the difference between Tottenham and City in Sunday's opener, but Spurs will be desperate to keep their talisman Kane, who collected his third Golden Boot with 23 Premier goals last term.
After the 1-0 victory – a result which represented City's third successive 1-0 loss and the first time that they have gone three games without scoring since 2007 – Nuno insisted that Spurs must be prepared for life without Kane, even if they are not anticipating selling their star man.
Inter's Lautaro Martinez is reportedly the main replacement target, though for the time being that move would be entirely dependent on Kane's potential departure.
And, as Nuno has stressed throughout this ongoing saga, he will continue to back his captain, despite not being able to offer assurances as to what may happen in the future.
"Tottenham have played without many players, eventually," the former Wolves head coach continued. "Tottenham have played with Harry. But it's always good when you can have all the players involved.
"There are not many managers who know exactly what's going to happen while the transfer window is open. We're all in the same situation.
"What we must be sure of is when we decide to put a player on the pitch, we must consider all the aspects.
"Harry has all our support. Today we had breakfast together."