Placed under investigation for match-fixing last month, Bonucci has been thrust into a starting role at the European Championship following injuries to fellow defenders Andrea Barzagli and Giorgio Chiellini.
Bonucci made a similar transformation from benchwarmer to protagonist with Juventus, helping the squad win the Serie A title last month.
He credits a mental coach with his sudden success.
“There was a lot of discussion about me, but I always kept the focus on football, which is my job,” Bonucci said Thursday. “Having dreamt as a kid to play with the national team shirt helped. That's what I thought about during the tough times.
“And my wife, who will soon make me a father, helped me push aside the things that were said, and my personal motivator (Alberto) Ferrarini helped me grow. I've gone from the tribune in Serie B to a starter with the national team. I work on thinking positively with him.”
Bonucci isn't just a starter now, he's also become a leader for Italy.
When temperamental forward Mario Balotelli nearly exploded with anger after scoring against Ireland, it was Bonucci who rushed to place his hand over the striker's mouth.
“I played with him on Inter's youth squad and I know him better than anyone else here,” Bonucci explained. “He was just 17 but I was already scolding him back then. That's just how he is, and that's why I took care of him during the celebration against Ireland. And he then thanked me for that.
“Unfortunately sometimes he does crazy things. He's spontaneous but he's a good kid,” Bonucci added. “If he can smile a bit more, he's a player who can make the difference for us. He's unpredictable, he's strong and he's powerful.”
While Italy will probably rely on Balotelli for goals in the quarterfinals against England on Sunday, Bonucci and Barzagli will have the job of stopping England star Wayne Rooney.
Barzagli returned from a calf injury against Ireland, but now Chiellini is out with a left leg muscle injury. Bonucci also plays with Barzagli and Chiellini at Juventus, where his performances helped persuade manager Antonio Conte to employ a three-man defense.
Italy coach Cesare Prandelli also used a three-man defense in the Azzurri's opening two matches, although it's unclear what strategy Prandelli will use against Rooney.
“We've started to study him, although England isn't just Rooney,” Bonucci said. “He's very skilled, but we need to play as a collective to negate their excellent quality up front.”
A couple of weeks ago, Bonucci was under the spotlight when he stayed with Italy while fullback Domenico Criscito was cut from squad because he, too, was placed under investigation for match-fixing.
“It upset me that he was cut out for non-football reasons,” Bonucci said. “Making a decision like that is never easy and whatever choice the federation made there were going to be pros and cons.”
Bonucci is being investigated for allegedly helping fix matches while he played for Bari in Serie B in 2009-10. He joined Juventus the following season.
Police showed up at Italy's training center in Florence to notify Criscito that he was under investigation, while Bonucci had already been called in for questioning by a prosecutor in Bari.
“I was just thinking about playing football,” Bonucci said. “I said everything I needed to say in Bari.”