There was a time when Gordon Strachan, the Celtic manager, appeared excessively pleased with himself for discovering and then signing Artur Boruc from Legia Warsaw in 2005. These days, though, the toll of the Pole’s misadventures must be making Strachan wonder where he goes from here with his talented, but gormless, goalkeeper.

Boruc’s blunder in letting John Rankin’s audacious, yet harmless, 45-yard punt elude him in Sunday’s Clydesdale Bank Premier League match at Easter Road was only the latest in a series of embarrassments for the player — both on the field and off it. Boruc these days isn’t just error-prone, but appears slovenly, out of shape and even a touch reckless. He has been an inspirational Celtic goalkeeper who now looks in genuine danger of burning out.

As one respected Celtic supporter said yesterday: “Boruc has been worshipped by the Celtic supporters but he is now testing that adoration to the limit.”

It would be tedious to explore the long list of Boruc setbacks of recent times — may it suffice to report his blunders have become a trend. When Rangers won 4-2 at Celtic Park in August many felt that Boruc, quite apart from his middle-finger gesture to the visiting support, was at fault with two of the goals, and the alarms raised then over his declining form have subsequently looked justified. Leo Beenhakker, the Poland coach who recently dropped Boruc after some late-night curfew-breaking, is only one in a queue of people despairing of the player’s antics.

The mistake Boruc made at Easter Road on Sunday is hardly the stuff of public floggings — Rankin’s shot did swerve and, from that distance, was about the last thing a goalkeeper would have expected — but for Celtic there is a one-man circus developing around Boruc which is unnerving. And at the core of it all is Boruc’s preposterous image — is it a deliberate piece of satire? — as the “Holy Goalie”.

On more than one occasion the Pole has been spotted carousing out and about in Glasgow, usually with a retinue of Polish pals or the usual hangers-on in his wake, and normally with alcohol as the lubricant of all the fun. On top of this is Boruc’s unfailing habit, notwithstanding the abuse he takes, for gesturing to opposition supporters, in particular those of Rangers. If this is holiness then, clearly, all the great Christian figures down the centuries have got it wrong.

It has been pointed out, with a germ of truth to it, that a group of Rangers fans lie awake at night nursing their hatred of the Celtic goalkeeper, and that Boruc’s life in Glasgow is not the easiest. Yet no end of this type of earnest sympathy for the player can justify his self-willed decline. Today Boruc is proving to be the master of his own downfall.

It has been better at times to view him as a comical figure rather than a serious one. On one recent occasion, not long after the famous moment when Boruc unveiled his Pope John Paul II T-shirt after the Old Firm match against Rangers at Celtic Park in April this year, an interviewer was keen to ask him about his allegiance to the Christian faith. “Do you actually go to church?” the interviewer asked Boruc. “Yes, yes,” came the blithe reply. Out of genuine interest the interviewer continued by asking Boruc: “Really? Which one?” At this point the bold Artur’s diction became muffled and unclear as he blurted something about “that one . . . you know . . . over there.”

Boruc is now causing a genuine headache for his club manager. Strachan, who resents the media’s public moralising about Boruc — apart from anything else the Celtic manager views it all as hypocritical — nonetheless will be among the foremost observers of his goalkeeper’s failings. The Celtic manager must now know there is a prime case for dropping Boruc, just as Walter Smith did earlier this season with Allan McGregor at Rangers.

Boruc’s talent cannot be questioned, but his mind and its dedication to his football career certainly can. It is claimed that, behind the scenes at Celtic, the goalkeeper employs a psychologist to gee him up for games. It only begs the question: has the shrink in question been on prolonged sabbatical, or maybe even carted away himself for psychiatric help?

Gone are the days when the likes of Manchester United, Arsenal and even Inter Milan were said to be interested in wresting Boruc from Celtic. Right now, the notion of a big-money bid from a leading European club for him seems laughable. Last season, when the omens still seemed good, Celtic put the 28-year-old Boruc on a new, long-term contract, but that piece of business now looks impulsive.

Tomorrow night Celtic play Villarreal at Celtic Park and Strachan will surely give thought to dropping the Pole for the club’s final — and largely irrelevant — Champions League group E game. Yet the problem for Strachan is that his back-up goalkeeper, Mark Brown, is thought to lack presence, while Dominic Cervi, Celtic’s third-choice goalkeeper, is believed not to be ready for such a European fixture. In which case, the chances are that Boruc will survive for the present in the Celtic team.

Celtic are still said to be pursuing Lukasz Zaluska, another Pole, who is presently with Dundee United. If they are then, for Strachan’s sake, it must be hoped Zaluska does not share Boruc’s unique appetite for piety and bevvy in equal measure. Clearly, it is a disorientating mix.