Brendan Rodgers had Celtic at hello. It is the goodbye that has left the sour taste.

Whether it lingers depends on just how seamless Neil Lennon’s return to the Celtic dug-out is.

In truth, the honeymoon seemed over long before Rodgers’ journey south of the border to the King Power stadium.

If the marriage was originally one of gushing, showy attraction, the cracks were evident in April last year when the first real opportunity to stray was presented.

In truth, there was little substance to the speculation that surrounded Rodgers when Arsene Wenger would be stepping down from his 20-year-post at the club. And yet there was something telling in how both Rodgers and Dermot Desmond, Celtic’s majority shareholder, reacted to the news.

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The Celtic manager used the chance to reaffirm that he was in his “dream job” yet was quick to present a detailed and compelling argument as to why Arsenal would want to pursue his services. Curiously, the usually reticent Desmond was happy to talk when a Sky TV camera was presented in his face at a golf tournament as he intimated that no-one would be standing in Rodgers’ way if there was the chance to hop into bed elsewhere.

And, of the many firsts that Brendan Rodgers’ enjoyed at Celtic as he rewrote the record books, yesterday’s was the most unpalatable for the Parkhead support; in the club’s 130 year history, Rodgers is the first Celtic manager to leave in the middle of a season having been seduced by the offer of a deal elsewhere.

For a man who placed great stock in his credentials as a Celtic supporter, it is not the fact that he has followed the money trail to another club but rather the timing of his move that has irked a section of the support.

And in the ramifications that follow now, there will be two camps; those whose disappointment at Rodgers’ departure turns to anger at leaving the club ahead of a pivotal three game spell that will shape the season and the ambitions surrounding an historic treble treble and those whose recriminations will be squared entirely at the door of the Celtic board.

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That particular narrative is one that Rodgers himself helped to shape.

In the middle of August last year in the Firhill boardroom, a post-match interview was played on the TV screens with a clutch of Celtic directors hanging on every word.

“I’ve always had a very, very good relationship with the board and that’s the same, even though some people will try to dismantle that,” said Rodgers, to a snort of derision.

His comments, in the aftermath of a League Cup win, came on the back of the most acrimonious month of his tenure at the club and followed a week in which Rodgers had used the pre-match press conference on the eve of the biggest game of the club’s season against AEK Athens to fire loaded bullets towards his board.

As Celtic prepared for the penultimate qualifier for the UEFA Champions League, Rodgers’ call that day to turn attention to what he perceived to be a lack of backing seemed almost like pre-emptive deflection.

With fingers pointed unambiguously towards the board, and Peter Lawwell in particular, there was little said about the £59m in the club’s annual wage bill, a tally that now sits at almost double from when Rodgers took over from Ronny Deila.

While tension has been interpreted in the working relationship between Lawwell and Rodgers – and the latter’s failure to mention the chief executive by name has been notable in the last eight months – it is Desmond who is believed to have been particularly aggrieved at the public undermining from Rodgers.

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Dedryck Boyata, the best central defender available to Celtic, did not play in either of those Champions League qualification games against AEK. The club had wanted to take the £9m offered by Fulham for the player going into the final year of his contract with almost three weeks of the transfer window still to run, a move that is understood to have become a resignation issue for Rodgers; had the club took the money on offer for the Belgian defender, Rodgers is alleged to have threatened to quit.

It got murkier still.

Even at noon on the final day of that awkward summer transfer window that brought into sharp focus the fact that all was not well behind closed doors, the word was that Celtic would not and could not sell Moussa Dembele. By the close of the play, the Frenchman was on his way to Lyon and Celtic had money in the bank but no way to spend it on a replacement.

Dembele has his own story to tell but the understanding was that by the time he left the club he had made it known to senior members of the club’s hierarchy that his relationship with Rodgers was irretrievable.

Lee Congerton, appointed head of scouting and brought in to replace John Park, was defended robustly by Rodgers both in January and in the summer. Asked about Congerton’s role one afternoon, Rodgers was uncharacteristically terse as he snapped that “he doesn’t sign the cheques.”

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As this played out, there were few who dealt with Rodgers on a regular basis who would have been surprised to see him go this summer.

In July before a Champions League qualifier, Rodgers washed his hands of the arrival of Daniel Arzani; last month the same scenario unfolded again as he insisted he knew little about Ukrainian winger Maryan Schved.

That Rodgers leaves a legacy is fair to say; seven trophies out of a possible seven is not to be sniffed at. If Celtic are successful in adding to the League Cup that has already been banked with an eighth successive title and a Scottish Cup then the 46-year-old will take ultimately take credit for the hand he had in it.

Publicly he had offered little indication that he would wish to be anywhere other than Celtic to an adoring audience hence the anger that greeted the news that he was prepared to quit for Leicester, who currently sit in 12th position in the English Premier League.

Like the man who will walk into his shoes now, Rodgers brought some of the thunder back to Celtic Park. The lethargy which characterised the end of Ronny Deila’s tenure at the club was shaken up entirely in that fabled Invincible season and there can be no doubt that he made Celtic a significant amount of money; the final tally would not be significantly shy of the £90m mark.

Yet, those Champions League night were bruising affairs too. Martin O’Neill, Lennon and Gordon Strachan all claimed big scalps with Celtic but they were sobering endurance tests under Rodgers as Celtic shut their eyes, took the hits and thought of the money.

That Rodgers got the best out of players he inherited is not to be ignored; James Forrest, Kieran Tierney, Callum McGregor and Scott Brown were all enhanced by the tutelage of Rodgers. What will be interesting to chart now is just who he might look to take to join him at Leicester.

That really wound be a final twisting of the knife.

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