Days after his 18th birthday he joined Ligue 2 side Metz, where he starred in a successful youth team before making the step up to the senior squad ahead of the 2010/11 campaign. He finished that season a regular in the side, totalling 19 appearances and scoring his first professional goal against Clermont as Metz narrowly avoided relegation.

Koulibaly caught the eye to the extent he was named in France’s Under-20 squad for that summer’s World Cup in Colombia. He played alongside the likes of Antoine Griezmann, Alexandre Lacazette and our own Gael Kakuta as France finished fourth, Koulibaly playing every minute of all but one game.

Although Metz could not escape relegation in 2011/12, it was another season of impressive development for Koulibaly, who even captained the side aged just 20 in a win at Monaco. Other clubs in Europe were starting to pay attention, and it was Genk who secured his services in June 2012.

Koulibaly thrived during his two years in Belgium. He sampled European football for the first time, making 18 appearances in the Europa League as Genk reached the knockout stages in both seasons, and won the Belgian Cup in 2013. Koulibaly was prominent as Standard Liege, Anderlecht and Cercle Bruges were all beaten en route to glory, Genk only conceding once when he was on the pitch.

He showcased his versatility, too, notably used in a defensive midfield role in a win over Sporting Lisbon, and more often at right-back, a position Napoli have also deployed him in. Koulibaly accumulated a healthy 92 appearances at Genk before departing for Serie A.

Naples has been Koulibaly’s home for the past eight years, and such is the standing in which he is held in the city he was made an honorary citizen in 2019. Known as a promoter of social justice and fervent campaigner against racism, particularly in the wake of racist abuse he received in Italy, Koulibaly has also done vital work in Senegal to help underprivileged children.

On the pitch, Koulibaly has proven one of Napoli’s greatest foreign imports. A regular throughout his eight seasons, he amassed 317 appearances and scored 14 goals. Koulibaly has been a major factor in Gli Azzurri establishing themselves as genuine title challengers in Italy, coming as close as they ever have to winning Serie A for the first time since the days of Diego Maradona and a young Gianfranco Zola.

Koulibaly’s maiden year in Naples included an Italian Super Cup win over Juventus, in which he scored the decisive penalty, and a genuine tilt at the Europa League as Rafa Benitez’s side reached the semi-finals.

The arrival of another former Chelsea boss, Maurizio Sarri, took Koulibaly’s game onto a new level. Given extra responsibility in possession, Koulibaly was encouraged to bring the ball out of defence. He took to the role admirably, named in the Serie A Team of the Year for 2015/16.

He would receive that accolade in each of the next three years, too, culminating in being voted Serie A’s best defender in 2019. For the second season running Napoli, now under the stewardship of Carlo Ancelotti, just missed out on the title to Juventus, but Koulibaly was a near ever-present and stood out with his anticipation, speed and assuredness in possession.

Napoli’s wait for the silverware their talented squad deserved ended in June 2020 when they beat Juventus on penalties in the Coppa Italia final following a goalless draw in which Koulibaly was immense.

Like for so many in the past two seasons, Covid-19, plus injury meant Koulibaly’s appearance figures slightly dropped, but he still played 71 games for Napoli in that time. That figure could have been higher had he not been captaining Senegal to Africa Cup of Nations glory earlier this year, the pinnacle of his international career to date.

Koulibaly made his debut for the Lions of Teranga in 2015 having opted to represent the country of his parents, and has been a regular ever since, accumulating 62 caps. He played all three of their group games at the 2018 World Cup, when Senegal were unlucky to miss out on qualification to the knockout stage, and was an ever-present until the final of the following year’s AFCON final, suspension ruling him out of the narrow loss to Algeria.

He and his country more than made up for that heartbreak in the next edition of the tournament, delayed because of the pandemic. Like Edou Mendy he missed the first two group games because of Covid, but recovered as Senegal navigated the knockout rounds and edged past Egypt on penalties in the final. Koulibaly scored his spot-kick and had his hands on the trophy shortly afterwards, sparking delirium in Dakar and beyond as his nation triumphed in the continental tournament for the very first time.