From one keeper to another: Celtic great on Joe Hart leaving on a high

Not just because he was leaving his boyhood club, and not because Celtic were the only team he'd played for at senior level – at that point in time, for the last 16 years – but because the decision was made behind his back.

"When I left Celtic the first time, Lou Macari was the manager and he told me in the car park outside the bus after we'd come back from Dundee United," said Bonner. "It doesn't always happen that you can set your own terms when you're leaving.

"I think it's good that you're organised, that you're able to let the club know. And you're able to win a championship."

Bonner left Celtic Park thereafter to Tommy Burns at Kilmarnock, the Irishman's friend and former teammate having spent the previous two years as manager at Rugby Park.

But when Macari was sacked in Glasgow's east end just weeks after the slighting kerbside chat he and Bonner had shared, Burns, and indeed Bonner, returned to Paradise.

Fast forward less than a year, and despite finishing fourth in the Scottish Premier League, Bonner marked his final game as a Celtic player with an historic Scottish Cup win.

With outgoing goalkeeper Joe Hart set to retire following this weekend's Scottish Cup final against Rangers at Hampden, there are certainly parallels between certain parts of Bonner and the Englishman's journeys.

At this point, no one knows how the final page of Hart's story will read, but reflecting on the adulation the 37-year-old received at Celtic Park last weekend – when Celtic's 3-2 win over St Mirren was capped off by a second title party in three days, this one in front of 60,000 fans – Bonner admires the situation Hart has earned for himself now on the cusp of leaving.

"Joe came up from England at a difficult time in his career," Bonner said. "He might not have been in the best frame of mind, mainly because his career had developed and finished off down there. I'm not sure he'd have known what to expect, but you could see the emotion from him and fans at Celtic Park last weekend, and it's been a really positive experience for him and one that he won't forget.

"I'm sure he'll look back on his time at Celtic in a really positive light, more so perhaps than what went on in other places. It's not a long time at the club, but I think that when you look at the reaction the fans have had and his own involvement over those three years, it's been very positive.

"He'll look back with positive memories, and his family will too. It's always nice when you're able to walk away from something and have good memories."

For Bonner, replacing Hart is a huge deal for Celtic. His on-pitch performances, stellar shot-stopping, and desire to help the team build from the back has formed the backbone of the current Celtic side – a character who's ensured and maintained continuity during the tenure of two high-profile managers.

Off the pitch, Bonner nods to Hart's charisma and experience, and admits traits like these are hard to come by on a case-by-case basis, even more so when one individual harnesses them all at once.

Goalkeepers at Celtic don't get to make 20 saves per game, says Bonner, nor do they get to claim 20 crosses, or have 20 through-balls to deal with. Instead, goalkeepers at Celtic are required to make big saves in big moments; steely, mental giants who thrive under pressure and are always ready when called upon.

"Joe has done exceptionally well," added Bonner. "Like all goalkeepers, he's made mistakes, we've made them. In terms of how the game has changed, building the game from the back, I think he's fitted in with that really well.

"He's shown that he's been able to adapt to that, and bring a little bit more composure to his game than might have had before.

"That might not have been the case as much when he was down in England, where people might not have believed in him as much as needed. It's all about confidence also, and working with him on the pitch and making sure he has got the opportunities to pass the ball out, and the whole team needs to give you that confidence.

"But the big thing for him is that he's made the big saves in the big moments at the right times. And he's been on a winning team – and that's the critical factor. Another two huge qualities that Joe has are experience and he's got personality. He's a leader on and off the pitch and you can see that within him."

At 37 years old, Hart is an older player, but not too old – especially given his position on the pitch. Italian goalkeeper Gianluigi Buffon called it a day playing for Parma at the age of 45, while Dutch legend Edwin van der Sar finished at Manchester United at 41, and played his last-ever professional game at 46.

Bonner himself was 35 when Celtic clinched the 1995 Scottish Cup against Airdrieonians, and was 1997 when he stepped away from football altogether.

Given the elite athleticism that underpins the modern game, the Irishman says he once reckoned Hart would have stayed playing for another year, even if that wasn't in the number one spot week-in, week-out. He recalls learning from Peter Latchford at Celtic and Gerry Paton in the Ireland international fold, and reckons Hart is more than cut out for a similar advisory role once he has hung up his gloves.

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Hart won't be doing that until the celebrations or commiserations following the Scottish Cup Final 2024 are done and dusted, but Bonner reiterates the joy that the Englishman can derive from his time in Glasgow now matter what happens against Rangers.

Celtic's outgoing number one is expected to lend himself to punditry during this summer's Euro 24. As a pundit himself, Bonner well-understands the pathway between playing the game and talking about it. But that doesn't mean the urge to be down on the grass ever leaves you.

Bonner added: "Joe must have thought long and hard about retiring from football. And then it's about what comes for him next – does he go into the media, does go into business, does he go into football, these are things that will likely be going through his head.

"He might just want a rest, he might just want to get away from it for a while. But I'm sure he's thought that out.

"Because, let's face it, when you do give up football, unless you go back into coaching, you miss it."