Bonucci explains: "I had that tattoo after the birth of my children. Basically, when you get married, you start searching for stability, and that stability was given by my wife [Martina] and my kids [Matteo and Lorenzo], so I felt really satisfied and rewarded. Apart from realising my dream as a football player, I had also obtained what I wanted in life."
Except, in 2016, Matteo fell ill and had to undergo emergency surgery. Bonucci considered quitting football. "Especially when we had problems with Matteo's health, when he fell ill — I did not ask for anything," Bonucci says, touching the tattoo. "I talked to God and I just told him 'it's up to you, it's your decision' and God listened to me and Matteo was able to start a second life."
It would be trite to say Bonucci is now enjoying a "second life" back at Juventus but it is a fresh start at least — even if United also came calling when it became clear his shock move to Milan was not working out.
"There have been some possibilities, both with Manchester City and Manchester United," Bonucci says. "With City, when I received an offer [in 2016], I talked to the club, I talked to Juventus, and we decided it was good for me to stay and keep on winning with Juventus. And this year, when I was told there was a possibility to come back to Juventus, I just stopped listening to any other offers and decided to come back here."
So there was an offer from United? "Yes," says Bonucci, in English. But there was no chance of you going there once Juventus were interested? "No," he says, again in English, before breaking back into Italian.
"I feel at home. Here, I really do my best, I just push myself to the maximum and that's something at Milan I really didn't manage, and that was probably because, in my heart, I had already made the decision I wanted to go back home.
"The decision was not made until June but it's true I had this feeling inside me. So when my agent told me there was an opportunity to go back, I stopped listening to anyone telling me what to do, I just said 'OK, let's go home'."
So why did he leave Juventus in the first place after such a remarkable career — six league titles, two Champions League finals — at the heart of Europe's most formidable defence?
"I made a decision driven by pride and I was upset by a specific situation," Bonucci says, alluding to an apparent row between himself and Juventus coach Massimiliano Allegri.
"And so I was not myself any more and I decided to leave. Then, with the passing of time, I realised I probably had the wrong attitude and so those expectations I believed were not met, well, it was not actually like that. So I changed my mind."
That was an honest response, I say. "Thank you," Bonucci replies, in English, adding in Italian: "Well, it was obviously a tough decision because not everybody would have accepted to come back and to admit a mistake like I did. I was also lucky because I was made welcome and accepted again by our president, our coach and the whole dressing room.
"So I decided I had to run this risk because it was worth taking and overcoming all the possible hurdles with the support of my family and Juventus itself. And that is what happened in the end. That is what the tattoo says."
Bonucci pauses and points to another tattoo, in Latin, under his left bicep. "Per aspera ad astra," it reads. "Through hardship to the stars."
Some players teased him on his return but, with others, he wanted to speak to them in person and explain.
"I wanted to clarify and better explain the reasons behind the decision, because they had told me they had not understood why I had wanted to leave. I told them that I probably could have been less proud at that time and, I confess, I probably had the wrong approach, the wrong attitude," Bonucci says, knowing he also had to win over Juventus' fans.
"Certainly, the supporters were probably the most sceptical of all because they felt betrayed by my decision. But I am really trying to do my best on and off the pitch and to prove, to really demonstrate, that being a player at Juventus is not just about wearing this jersey. It goes beyond that, so I will always do my best to convince them I am worthy of it."
Juventus are unbeaten this season, recording 10 straight wins, including six clean sheets, in all competitions before the 1-1 draw against Genoa a week ago, and it is fascinating to hear Bonucci talk about what being a defender means.
"Defending is definitely an art," he says, explaining how he has learnt from Giorgio Chiellini and Andrea Barzagli, the other feted members of the original "BBC".
"What I have done is 'stealing' by observing them with my eyes what they were doing, because they are icons of world football and for someone like me who became a defender quite late, it was vital to watch them, learn from them."
Having started out as a midfielder — he could have been the ball-playing centre-half Jose Mourinho craves at United — Bonucci is allowed to "set the play" but his "fundamental" role is clear: stop the opposition scoring.
"I defend my goal as if it were my home. I do my best to defend it and not to allow anyone to score goals or penetrate that. It's true. Defence for me is so important because I do not want anyone to trespass and invade my property because that goal is my property. So that is one of the secrets that has allowed Juventus to win seven Scudetto in a row."
And, finally, win the Champions League?
"It is our main goal, our main objective," Bonucci says, with the first target to finish top of Group H ahead of United and Valencia. "It's true they [United] are going through a critical moment with Mourinho, but apart from that, they all know what they want and how to achieve that."
Bonucci was not the only surprise signing Juventus made last summer.
"Cristiano Ronaldo's arrival has been fundamental," he says. "He plays a crucial role because he helps our whole club grow a lot — the players, the club and certainly it was fundamental because it asked us to do something more: to raise the bar, basically, and we can also see that with the organisation and with the contact with the fans. So we have all improved — starting with the players, going through the club and to the supporters themselves."
- Telegraph Group Ltd
