ONCE you accept football’s insanity that allows players to be treated like cattle and sold off at a crazy prices that bear no relation to reality, you have to appreciate a good deal when it is done. That’s why by far the best bit of transfer business this summer so far has been by Celtic.

Kieran Tierney’s departure from Celtic was as lucrative for the club as it was inevitable, and with £25m to be banked, the outcome of the deal may just have been the Parkhead club winning their ninth title in a row and possibly several more after that.

For with at least £20m still in the bank even after signing Christopher Jullien and Boli Bolingoli-Mbombo and the possibility of Champions League group stage income – at least £25m – on the way or £5m if they crash out in the qualifying round, Celtic are in very good shape financially, though they remain relative poor boys of the European scene

I fully expect them to make a couple more signings at least in this transfer window – Scott McKenna of Aberdeen for one – and Champions League group stages or not, the triple treble winners have plenty millions available should they need to strengthen the squad at the January window. So kudos to Peter Lawwell, and Dermot Desmond and the board for not just accepting Arsenal’s first bid, and for holding out to get what Tierney is certainly worth – and the sell-on 10% clause will gain Celtic even more once the biggest boys come calling for the Scotland international as I am sure they will.

Nine in a row is the least they need to do domestically but it’s what Celtic do in Europe that matters this season. It is vital that they beat Cluj this week, for otherwise, they will drop in to the Europa League play offs against either Sheriff Tiraspol of Moldova or AIK of Sweden and the latter is a risky bet. Beat Cluj and they are guaranteed European football. Beat Slavia Prague and it’s the Champions League group stages – and remember, only one current manager in Scottish football has steered his team through to the last 16 of the premier tournament, so can Neil Lennon do it again?

That being said, they will not win the league at a canter, and a quadruple treble is unlikely as they are due a bad game in the Scottish Cup and League Cup at some point, but Celtic’s only real challengers for the title are Rangers and they simply do not have the financial resources at the moment – their biggest signing of the summer, Filip Helander, cost £3.5m, half the price of Jullien – to buy the sort of players Steven Gerrard will need to continue the club’s undoubted improvement since his arrival.

Those few Celtic fans critical of Tierney for going, and the club for selling him, need to do some arithmetic. In one deal, Celtic have recouped all the money and much more than they laid out for the Lennoxtown training centre where Tierney learned his trade. The real question is whether Celtic will now invest in producing even more young Scottish talent. Kieran Tierney is the absolute proof that such youth investment can work for both club and player.

There is simply not enough money in the Scottish game for Celtic to compete on the European stage as equals with the likes of Manchester United, Barcelona, Real Madrid, Juventus or the big French and German clubs, so I’m afraid that, like every other Scottish club, Celtic will sell their best players if the price is right.

Rangers looked very impressive in midweek and having learned some harsh lessons last season, Gerrard will get his team to cut out the sloppy errors against smaller clubs which cost them so dear. But he faces a dilemma, as does Neil Lennon – it’s well known that both clubs have exciting young prospects, but can they be stepped up to the first team this season? Will there come a time when Gerrard, for example, is forced to blood players that should really not be risked just yet?

That’s why the Tierney deal gives Celtic an advantage – Lennon now has a huge insurance policy that will enable him to bring on the likes of Karamoko Dembele and Ewan Henderson at a pace suitable for them. Gerrard has plenty young players with serious talent such as Dapo Mebude and Josh McPake, but will he have to rush them into the team if, say, the summer signings don’t work out?

It’s awful that everything in professional football comes down to money, but that’s the nature of the beast. And for all their domestic superiority, Celtic’s fans got a major lesson this week – when it comes to hard cash, Celtic are not in the highest echelon. Sure the club has an excellent business model that’s far superior to every other club in Scotland, but in European terms, they’re second division.

You could say that about another once legendary team who dominated their own league for years, namely Ajax of Amsterdam. They are giants in the Netherlands but in European terms they struggled, until last season, when they bested Real Madrid and Juventus before that unforgettable semi-final with Spurs.

Do an Ajax and get to the semi-finals and Celtic will be able to say they are back on the European stage.