When Kalidou Koulibaly called the Chelsea great to ask permission to inherit his old shirt number, John Terry initially hung up in disbelief, according to Koulibaly.

Because it was Terry's former Napoli jersey number and because both the Senegal captain and his wife Charline Oudenot were born on the same day, June 20, in the same French hospital, the No. 26 has special meaning for both Terry and Koulibaly, a £34 million summer purchase.

This week, a video of Koulibaly asking Terry, who was visibly shaken, if he could wear the shirt that had been vacant since the latter's departure in 2017, went viral on social media. Koulibaly said: "At first, he didn't believe it was me. He put the phone down after asking the team manager if it was actually me since he assumed it was a joke.

After I asked him respectfully that I wanted to take his number - and I know it was for him a very important number - but it is an important number for me because I took it directly when I went to Napoli and I wanted to keep it here at Chelsea. When he told me yes, I was really happy because I know what he did for the club, the supporters, and the city here.

'It was very important for me to ask him and he gave me his answer. I was happy and I wanted to tell everybody that I asked him before because I don't want to be disrespectful to a legend of the club.'

Had things developed differently, Koulibaly, 31, and Terry could have been Chelsea team-mates before the latter left.

'I spoke with [former Chelsea manager Antonio] Conte in Roma - he wanted me after my first good year in Napoli,' Koulibaly explained.

"I had three or four years left on my contract with Napoli, but I don't like to argue with my owner or my fans to leave."

I politely informed the owner that I wanted to move to Chelsea, but he informed me that this was not possible.

They genuinely didn't want me to leave the club, so I chose to renew my contract to stay at Napoli after a little while of waiting and talking with them.

Growing up, his brother Koulibaly Abdoulaye forced him to watch Chelsea matches. The Didier Drogba period and his 2012 Champions League-winning penalty are among the memories that will always stick in his memory.

The legendary Blues player Gianfranco Zola, who helped him connect with Terry and offered Koulibaly a history lesson about Chelsea, is a mutual friend with him back in Italy.

Edouard Mendy, a Chelsea goalkeeper and Senegal teammate, is someone Koulibaly considers "a brother," and with Jorginho, a Chelsea teammate from their time together at Napoli, "I had double pressure on me," he said. However, it wasn't terrible and was pleasant.

He has had to be patient but now after years of links, also with the likes of Manchester United, Liverpool and Manchester City, Koulibaly has finally got his wish of a move to England.

Koulibaly, who revealed he received text messages congratulating him on his choice from 'legends' Drogba, Zola, Terry and countryman and ex-Chelsea striker Demba Ba, said: 'I am really happy and thankful to them and want to show them that I will give everything for this club and maybe one day be part of them.

'It was a bit hard to say no to the Premier League [previously when Chelsea asked] because it was my dream to play in the Premier League since I was a child. But I knew that one day it would happen and I'm happy that it had.

'I never stopped believing. This is most important. Some dreams happen. My dream with my national team was to win the first AFCON and we did it. So, for me, you never have to stop believing. 

'If you believe so strong afterwards it can happen. I knew everybody was thinking I would never come to Premier League, never play for nobody else than Napoli but I make my choice with my family and friends and the people that love me and I decide and thought this is the good time to come to Premier League.

'I am happy to sign for Chelsea today and to continue to play with [the colour] blue. I am happy and the decoration for my house is better!'