Adrian Peterson practices with Vikings for first time since September

MINNEAPOLIS – Donning his purple No. 28 jersey for the first time in nine months, Adrian Peterson said Tuesday he has apologized to the 4-year-old son he struck with a wooden switch and had “learned a lot from my mistake.”

Peterson returned to the Vikings and practiced for the first time since September. He then told reporters he has met all the requirements that came from pleading no contest to a misdemeanor that caused him to miss the final 15 games of last season.

“I made a mistake,” Peterson said. “I know a lot of people don’t view it that way based from what they’ve seen, but ultimately that’s what it was. My son knows that, he knows I love him. And my other kids know the same.”

Peterson was placed on the commissioner’s exempt list last September after he was charged with felony child abuse in Texas. The photos of the wounds that the boy suffered at Peterson’s hands brought harsh criticism of the once-beloved face of the franchise and prompted sponsors to sever ties with him and the Vikings.

He has gone through counseling and therapy sessions as part of his plea agreement and had several supervised visits with his son to monitor how the two interacted. Peterson said he has learned that the form of discipline he used was no longer acceptable and now he uses other punishments like timeouts and taking toys away.

The relationship between the team and its franchise player has been tense since the abuse allegations first surfaced. He was angered by a perceived lack of support from some members of the organization, namely chief operating officer Kevin Warren.

Shortly after Peterson was reinstated by the league in April, his representatives initially pushed for a trade to get him a fresh start. When that didn’t happen, the focus turned to his contract. Just last week, he vented on Twitter about the details.

Suddenly, Peterson seems ready to put all of that behind him.

The 30-year-old will have his $12.75 million salary for 2015 guaranteed in Week 1, but all bets are off after that. Peterson’s search for more guaranteed money in the final two years of his deal brought even more criticism from fans who believed he should be grateful for the organization’s continued support.