It started as an innocent greeting to some former colleagues and almost ended up burying a fresh start before it had really begun. After Porto’s first match of the Champions League group stage at home to Besiktas in September, Vincent Aboubakar popped his head around the door of the visitors’ dressing room to say hello to his former team-mates.

That was natural enough, given he had won Turkish title with them and they had reached a Europa League quarter-final together while he was on loan at the Istanbul club in 2016-17. He had been so implicated, in fact, he sat out this reunion because of a suspension accrued playing in Europe for Besiktas.

There was just one problem. Videos later circulated on social media of Aboubakar laughing amid a circle of dancing Besiktas players in the dressing room – all of which might not have been such a big deal had the Black Eagles not just won 3-1 at the Dragão, heavily compromising the Portuguese club’s European hopes.

A red-faced Aboubakar apologised, more than once, which was required with the club irritated and many fans outraged. It had been innocent enough but the Cameroonian striker, a dedicated professional but one with a strong sense of life and relationships outside of football, had taken a minute to absorb just how it had looked.

“They started to dance, just as I used to do,” Aboubakar told the club magazine Revista Dragões. “I started to laugh, and [Ryan] Babel started to film it. He didn’t deliberately upload it [publicly].” He took the opportunity in the interview “to apologise one more time, to the president, to my team-mates, to the directors and the supporters”.

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Nothing says sorry, though, quite like goals do and it is fair to say that, five months on, all is forgiven. Having looked expendable for most of the summer, the 26-year-old is in the form of his life, having scored 15 times in 20 Liga starts this season, with another five in five in the Champions League ahead of Liverpool’s arrival. Per se, this story is the sort which is 10-a-penny in Portuguese football. It’s a selling economy and when first-choice players are shipped out, some of those who were marginalised, cast aside and even forgotten are rehabilitated into the first-team picture.

Aboubakar’s story is slightly different, even setting aside his faux pas in the Besiktas dressing room. In November 2016, a couple of months into his season’s loan in Turkey, he told journalists unequivocally he would “never” return to Porto, rather than toeing a party line or bluffing about keeping options open. Spending his first season in Portugal as understudy to the prolific Jackson Martínez, and even playing more regularly after the Colombian’s exit to Atlético Madrid, Aboubakar has spoken of never feeling truly valued in his first two years at the Dragão.

The seeds of that were in the fraught nature of his 2014 arrival from Lorient. With a €10m transfer agreed, the medical showed up a knee complaint. Porto got twitchy but Lorient, led by their canny president, Loïc Féry, were not about to roll over. The clubs came to an agreement which maintained Aboubakar’s value pro rata, with Porto buying 30% of his economic rights for €3m.

Now Porto’s coach, Sérgio Conceição, has changed everything for Aboubakar and his team-mates. He has steered the club to the Liga summit, unbeaten 21 games in, after a desperate, trophyless run that stretches back to 2013. “This coach,” Aboubakar told France Football’s Nabil Djellit in December, “he does everything to make sure I feel implicated in this project.” The same has been true of other cast-offs such as Moussa Marega, Aboubakar’s top-scoring strike partner, and Sérgio Oliveira.

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Conceição’s tactics suit Aboubakar down to the ground. He favours a very attack-minded 4-4-2, with a decidedly un-Portuguese physical edge to it. It largely replicates the system in which Aboubakar first flourished in Europe, under Christian Gourcuff in his season at Lorient. “I already knew Aboubakar from Lorient,” Conceição told French journalists after December’s Champions League demolition of Monaco. “I love these type of strikers.”

The former Nantes coach, praised by Aboubakar for his “directness”, admits that it could have been very different had Porto not been operating on reduced means. “I arrived at the club, understood our reality and preferred to have Aboubakar with me,” he said. That feeling of mutual advantage was reciprocated, with the burly striker preferring to stick with Porto ahead of a summer offer from Marseille, which he saw as an unpredictable new project – for which he might have been the fall guy if things got tough.

Aboubakar’s judgment has proved impeccable. Porto extended his expiring contract to 2021 in October, also buying up his remaining rights from Lorient. The “reality” underlined by Conceição is that Premier League clubs are circling, as Aboubakar is aware, and the club have set themselves up to fully cash in. If he can unsettle Liverpool as he did Monaco in the autumn, his next set of video highlights might be rather better received.