Five months after having three bids knocked back, La Liga giants Barca finally got their man this week as Coutinho arrived at Camp Nou in a £142m transfer.
Kane is no stranger to transfer speculation himself, having been strongly linked with a move to Real Madrid for the best part of a year, and the England international admits that player power will almost always prevail.
"It's a matter of opinion, but I think if a player wants to go then why would you stop him?" he told reporters. "He's not going to be in the club, he's not going to play every game, he's not going to put his heart on the line so...
"From the Coutinho point of view I think he's been very professional in the six months he has played this year and, look, Liverpool have got a good offer from Barca and accepted it so I wouldn't say they're powerless, but I can see why if a player wants to go you would let him go."
Kane also reiterated that he is "happy" at Tottenham, but rubbished suggestions of discussions being underway over a contract extension.