From his interception as a rookie in the final seconds of the NFC Championship Game that clinched the trip to Super Bowl XLV to his Pro Bowl season of 2014 and right up until the opener of the 2016 season in Jacksonville, his last game with the Packers, the popular cornerback had plenty of reasons to flash it.
If Shields, 30, hadn't been the outgoing and well-liked teammate that he was, then perhaps no one in Green Bay would have cared that after five documented concussions as a pro and nearly two seasons out of football, he wanted to return -- and return for little more than a minimum contract.
Instead, there were plenty who thought it was a bad idea.
"At one point I was on the bandwagon with him like, man, you need to call it quits," said Packers cornerback Tramon Williams, one of Shields' early mentors in Green Bay.
That seemed to be the prevailing thought the last time Shields spent with his old team. It was in Atlanta for the NFC title game following the 2016 season. Shields, four months removed from the concussion that ended his season -- and as it turned out his Packers career -- said he was still experiencing headaches and other symptoms.
The Packers released him in February 2017 with the failed physical designation. Neither then-general manager Ted Thompson nor coach Mike McCarthy was willing to put him at risk again.
But it was always Shields' intention to play again.
The Los Angeles Rams finally gave him that chance this season, albeit with no risk on their end. The Rams gave Shields no guaranteed money, a minimum base salary of $915,000 and a roster bonus of $89,998. They even put a split salary in his deal, which means if he winds up on injured reserve, his weekly check would be paid at slightly more than half the rate of his base salary.
Even though the Packers now must face him on Sunday, his former teammates and coaches seem thrilled with the way it turned out.
"I'm just happy he's healthy," Packers coach Mike McCarthy said. "I know the last time I saw Sam was the 2016 NFC Championship Game and he was still recovering. I'm just glad he's healthy and what's best for him and his family."
Shields now plays for far less than the $9 million he would have made in 2017 had the Packers not released him with one year left on a four-year, $39 million deal. It's also not much money relative to the long-term risk of another head injury.
"Sam and I had a number of conversations about [playing again]," said Joe Whitt, Shields' longtime position coach with the Packers. "First off, I don't think people really realize how good Sam was in what we did, what he did for us. I mean, in 2015, the last year -- I know nobody wants to write about it, because we haven't been very good in the secondary the past two years -- but with him and Casey [Hayward] back there, we were the only secondary in the league that was top 10 in every major pass category. It was because of Sam and because of Casey. And when Sam went down in '16 in that first game, not only did it hurt the team, but he's a guy that helped us win the Super Bowl, and helped me provide for my family.
"So I'm really close to him, really attached to him and I wanted what's best for him. Once he got to a point where he felt like he could play again, and he assured me he could play again -- now, he didn't ask me, because he doesn't need to ask me permission for anything -- but we talked about it. He said, ‘Joe, I can play.' I said, ‘If you feel like you can play, then go do it. You know your body.' He's a great, young man. I'm glad that he's having success up there. I've seen a couple of his plays, and I'm just happy for him. I couldn't be more happy for him."
Shields moved into a starting role for the Rams last month, and his play has started to resemble his old ways on the field.
"Just keeping in touch with him during his time away after the injury in Jacksonville, this is what he wanted," Packers quarterback Aaron Rodgers said. "He wanted to come back; he wanted to come back here. But I'm happy he's playing. I'm happy he's feeling great. He's having no issues with his head.
"He's a fantastic guy, was a great teammate for us and a big-time player for a number of years starting with his interception in the NFC Championship Game and continuing on to the number of great plays he made over the years. It's been fun to be his teammate and now watch him back in the league."