I HAVE been wracking my brains for a while now and just the other day I eventually came up with an answer.

Henrik Larsson.

Let me explain. In all my time associated with Celtic, as a player, former player and now supporter, my old team-mate, a decent centre-forward as it so happens, is the only one I can think who was/is as loved as Kieran Tierney.

Read more: John Hartson: Let me explain why I said Deryck Boyata was worth £50m

Now that is one compliment to give to the kid from Motherwell.

I got a lot of love from the fans. So, too, Neil Lennon, Stan Petrov and right now Scott Brown is an icon and rightly so.

But KT really is ‘one of our own.’

If you permit me to talk about myself for a second, I played for some great clubs, Arsenal and West Ham United are famous names throughout the football world, and I proudly represented my country many times.

The fans could see me for what I was, in many ways, one of them in that I gave everything and stayed humble; something my dad drove into me when I started out.

But it was with Celtic where I felt real devotion from the faithful and I still do. At that so, so special club, if you do the business then you will be looked after like no other footballer on the planet.

Read more: Celtic have offer for Hibernian's John McGinn rejected​

I was the most expensive teenager in British football history when I moved from Luton Town to Arsenal where I was taken in by the supporters. It wasn’t Celtic.

I broke then transfer records at West Ham and Wimbledon and I wouldn’t change a thing. It wasn’t Celtic.

And I wasn’t brought up a Celtic supporter from just outside of Glasgow who went to the games on a supporters’ bus. Young Mr Tierney did.

KT is the hero. He is the fan on the pitch. Had he not been brilliant at football, he would be standing in the corner with all his pals. Is it any wonder, in my view, that no Celtic player has been idolised since that Swedish bloke.

He loves Celtic. Everyone knows that. He said just recently that if he could stay at the club for the rest of his career then his dreams would come true. Ah, but you just know what it coming.

But. There is always a but.

Read more: Brendan Rodgers: Celtic's Scott Sinclair was off pace from day one last season - he's back to his best now​

Put yourself in his shoes. Everton will come in with a serious bid, and Tottenham have been mentioned as well, and the lad has a big decision to make.

Brendan Rodgers himself said he would never stand in his player’s way if a club met the valuation, which I see as £25m-plus, and his wages would be as much as esven times what he’s on now – and that’s hardly peanuts.

Here is a question. What would you do?

Everton is a great club. The English Premier League is over-hyped; however, that isn’t to say that it’s an outstanding place to play your football. Hey, take it from a man who knows.

And, of course, Tierney could play down there. That isn’t even up for debate.

I have him down as just about the best left back in the country, and by that I mean Britain.

Read more: John Hartson: Let me explain why I said Deryck Boyata was worth £50m

He turned 21 just a couple of weeks ago so he is a baby, in my eyes at least, but he plays football like a man.

At £25m he would be the most expensive Scottish player ever. The money swirling around England is ridiculous, but this is about the right fee for such a talent.

The big question now is: what will he do?

I am certainly not going to give Tierney any advice. All I can do is think about what I would be thinking if I were him.

I would stay at least until the Champions League qualifiers were done and then after that…one or two more seasons and then I’d go.

I know what it’s like to have clubs interested in you. It is exciting, does a lot for the old ego and anyone would find it next to impossible not to be affected by someone wanting you – and happy to pay you a fortune.

Time is on Tierney’s side. His price tag is only going to go up. He could play with Celtic for another year, gain some more experience, and then make the move we all knew would come.

Whatever he does, whichever clubs gets to have him, this is a top class person and footballer who deserves nothing but the best.

He might go. If he does, good luck to him. He will get a big club, a big pay rise and he’s already part of Celtic folklore.

However, it is worth repeating that there is nowhere better to play than Celtic Park. Ask anyone lucky enough to pull on that jersey. The Premier League is one hell of a temptation.

But Celtic is a hard place to leave.