Jozo Simunovic was part of a golden era in Celtic's history. But the defender may still reflect on his trophy-laden Hoops career and wonder 'what if'.

Hoops chiefs bucked a trend by forking out a bumper £5.5million on the Croatian defender in 2015 as Ronny Deila swooped to replace the colossal Virgil van Dijk. Highly-rated at Dinamo Zagreb, Simunovic's capture was hailed a major coup as the 21-year-old put pen to paper on a five-year deal. However, just like the rest of his time in Glasgow, the stopper's debut campaign would be curtailed by injury - restricting him to just 17 appearances across all competitions.

A quick-fire exit the following summer was on the cards as Simunovic travelled to Italy to undergo a medical with Torino, only for the deal to collapse at the final hurdle as both clubs failed to thrash out a fee. The likeable centre-back was given a clean slate under new boss Brendan Rodgers and forced his way back into the fold - emerging from the shadows as first-choice defender alongside Dedryck Boyata and Erik Sviatchenko.

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While Simunovic managed to get his hands on all three domestic prizes that year, his crowning moment was his infamous crunching of Kenny Miller as Celts battered Rangers 5-1 at Ibrox. The no-nonsense Croat threw himself in to win the ball and connected with force but his follow through sent the striker flying in spectacular fashion. Simunovic wasn't booked for the challenge that soon went viral on social media and confessed years later that it ranked as a career favourite.

He recalled: "The tackle! Yeah, I know I will always be remembered for that too. That became a big thing – all around the world. The clip of the tackle is on social media all the time but it was a good, clear challenge. It was at Ibrox and I know that it will always be remembered. We also won 5-1 there that day and it was great. My tackle was fitting – as we completely smashed everything that season!"

Smash everything Celtic did, as Rodgers' men cemented their place in history by romping to an iconic Invincible Treble. It was Simunovic's finest season in a green-and-white jersey, and although more Trebles would follow, injuries would hamper his game time. A man who wore his heart on his sleeve, it was hard not to feel sorry for Simunovic as he gradually fell down the pecking order.

Yet while THAT tackle on Miller will live long in the memory of Celtic fans, Simunovic reserved his own special place in history by paying the ultimate tribute to the late, great Billy McNeill. Wearing Cesar's famed No5 jersey, Simunovic netted a poignant 67th-minute winner against Kilmarnock just days after the death of Lisbon Lions captain - a truly hair-raising moment for the 60,000 fans inside Parkhead.

"I’m going to remember that day for the rest of my life", he said. "That was maybe my best day at Celtic. It was a very strange day. We had lost Big Billy and then it was hard to focus on the game after all that had happened, but in the end, I scored as the number 5, for Big Billy, who was number 5, so I couldn’t ask for more."

Simunovic showed his class after the game by presenting McNeill's wife, Liz, with his match-worn jersey. He said: "That was my duty, after all, because that game was more for Big Billy than for myself. That day I never thought about myself."

There can be no room for sentiment in football, though. A year later, Simunovic found himself on the scrapheap after he was surprisingly binned by Neil Lennon as Covid brought the 2019/20 season to a premature end. It was a sore one to take but the gutted star has never held any grudges - hailing Celtic "as a special place".

Simunovic's luckless injury record combined with the global pandemic forced the Treble-winner out of football for more than two years. He eventually found a way back into the game with HNK Gorica in his homeland, but left after just a handful of appearances. In recent years, Simunovic has planned for life away from the pitch by completing a sports management degree and his coaching badges.

And after two years without a club, retired Simunovic has decided to venture into management by taking on his first job as Under-19s boss of Dinamo Zagreb at the age of 30. A popular figure on and off the park, injuries undoubtedly halted Simunovic fulfilling his potential at Parkhead. Now, the former fans' favourite will embark on a fresh start as he attempts to cut his teeth in the dugout.