His public image and personal brand took a huge hit. He had to miss 15 precious games in a sport with so few. He found himself thoroughly baffled by what to do next, whether he even wanted to return to the NFL, let alone Minnesota. He turned 30.
With that purple No. 28 jersey finally back on, though, he almost felt like he never left.
''It felt good to be back in the building, to be around the fellas,'' Peterson said Tuesday after his first workout at Vikings headquarters since Sept. 12, a practice that took place hours before his indictment on the child abuse charge that forever changed his life, disordered Minnesota's 2014 season and became part of the frame of an ugly fall for the NFL amid persistent domestic violence problems.
Despite his stated uneasiness with certain people in the Vikings' organization and the backlash against him around the region following the injuries he caused while disciplining his son, the relationships Peterson built over his first eight years with the team were what drove him to drop his informal protest and arrive this week to work.
''It's been a lot of love that I've felt through this process, and I was able to feel that same love today,'' Peterson said.
He shared many hugs with players, coaches and staff, but after all the tension, confusion and bitterness of the last several months when his departure from Minnesota appeared inevitable there was a back-to-business vibe at Winter Park on the day of his return. Peterson didn't even give a special address to the rest of the team, another sign of the respect he's long had in the locker room.
''He's got such a charismatic smile, infectious personality. It's good to get him here,'' coach Mike Zimmer said.
On the field, Peterson has some catching up to do, but he already had months of experience in offensive coordinator Norv Turner's scheme last season before he was put on paid leave while the
''We tried to get him acclimated on the things that were going. He's going to have to put in some more work time as far as all that,'' Zimmer said, ''but there's really not a prettier sight when he's got the ball in his hand, you know?''
The Vikings finished 7-9 in Zimmer's first season, a decent accomplishment considering Peterson's absence and the steep learning curve for rookie quarterback Teddy Bridgewater, but they weren't happy about it. Now, barring injuries, Zimmer and Turner will have the full lineup on offense they originally envisioned.
''I do believe that we can be very, very explosive,'' Zimmer said. ''I think to have a talented running back with a talented quarterback and talented receivers and some good tight ends, I think that we can spread the field and it can be good for everyone.''
Peterson reiterated his apology to his young son for spanking him with a wooden switch, describing the act as a mistake. He said loves his children with all of his heart and would ''jump in front of a car for them.''
He said his softened stance on returning to Minnesota came through prayer, counsel from trusted pastors and good old-fashioned listening to mom and dad.
''With everything going on in my life at that time, I really didn't know what I wanted,'' Peterson said. ''I really didn't know if I wanted to play somewhere else, if I wanted to retire. I didn't know if I wanted to get into track and do something different. That's where receiving advice from my parents, my advisers, really played a big role.''
Peterson's $12.75 million salary for 2015 will be guaranteed the first week of the season, but beyond that all bets are off. His agent, Ben Dogra, has pushed for a restructured contact, but the Vikings have made no assurances.
So Peterson, naturally, will be playing with plenty to prove. He'll also, despite being an age that's often unfriendly to running backs, be playing with a body that benefited from an unexpected late-career year of respite from the constant pounding taken from carrying the ball.
''I feel good, you know? I'm not going to say any names, but there's young guys I work out with in Houston, younger guys, like 24, 25, first-year guys just going to play, and I outrun them and out-jump `em and everything else,'' Peterson said. ''So with that being said, age is just a number. It's all about how you view it mentally.''
AP Sports Writer Jon Krawczynski contributed to this report.
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