The Celtic first-team coach says he can’t put a price on his young star – at a time when full-back fees are soaring, with Manchester City having paid Tottenham £50m for Kyle Walker and Chelsea offering Spurs £40m for Danny Rose.
Tierney, still just 20, has already won two championship medals, a Scottish Cup, four Scotland caps and, on Wednesday against Kilmarnock, captained his club.
Celtic legend Danny McGrain, in contrast, had yet to make his first-team debut at the same age.
And, with Tierney having been a boyhood Celtic fan, Kennedy belives that, while he could comfortably slot into the starting line-ups of the richest clubs in England, Tierney may even become a one-club man.
Kennedy said: “Kieran could go and play in the top four in the Premier League no problem. I’ve no issue with that but it wouldn’t surprise me if KT became the Paul McStay of his generation and stayed here.
“He loves the club, the fans love him, he’s in a terrific place and is really happy here. Not once has he spoken about going somewhere else.
“You can see the commitment he shows in games.
“What people don’t see is the commitment he shows day-in, day-out on the training pitch.
“He could go and play at a very high level. Would he stay at Celtic for his entire career? You never know. It wouldn’t surprise me.”
Should that come to pass, Tierney would be even more revered by the support and that is partly why Kennedy regards him as priceless.
“It’s hard to put a price on him, it’s hard to judge the market,” said Kennedy.
“If you’re based in England the price is very inflated. When you’re anywhere else around Europe, it’s not quite the same.
“However, he’s become a really big player for us. He got the honour of being captain there in midweek and it was thoroughly deserved. It’s not just a token gesture because the fans like him – it’s because of what he’s done in the past two years – the performances he puts in and the leadership he shows for such a young player.
“For us, he’s priceless because he’s a terrific player. We allowed Emilio Estevez to move on and we know we’ve got young Calvin Miller who can come in and we’ve used Callum McGregor there, too. So we’ve got enough cover.
“But KT is obviously the established left-back and the performances he’s produced for us in the past two seasons have been top notch. “