Joe Hart is Celtic problem needing solved as keeper with a frogman’s feet will always have unwanted consequences - Hugh Keevins

Brendan Rodgers came up with a nice line in amateur psychology the other day. Celtic’s manager was making a point about the human condition as it applies to football fans in general. Brendan might be thought of as something of an expert in this particular field, of course.

Thousands turned up just to watch him hold a Celtic scarf above his head when he first became manager of the club in 2017. Two years later, banners were held up decrying him as a “Fraud” with no respect for the club when, seven trophy wins later, he left Glasgow to manage Leicester City.

The people who were holding up the banners about fraudulent behaviour and Brendan having traded “Immortality” for “Mediocrity” are collectively known as the Green Brigade. They were conspicuous by their absence on Tuesday night when James Forrest had his testimonial match against Athletic Bilbao, a game which marked Rodgers’ return to Celtic Park in what was the club’s only pre-season friendly to be played at home. Tens of thousands turned up to pay homage to the player and their ticket money went, in large part, to Celtic’s Charity Foundation.

Charity, might I remind you, being the reason why the club was brought into being in the first place. You would have thought the Green Brigade would have respected history and ignored all other considerations for one night only. But Celtic raise title-winning flags and they lower the tone. That’s the way it works. Rodgers’ way of summing up supporters’ thought processes was to say they “Forgive when it suits and forget when it’s convenient.”

Not when it’s a defeat in an Old Firm derby, they don’t, Brendan, as any behavioural psychologist worth his university degree will tell you. Forgiveness, under those circumstances, is