Minnesota Vikings running back Adrian Peterson has been suspended without pay for at least the rest of the 2014 season, the NFL said in a press release. Under the terms of the punishment, Peterson, who pled no contest to a misdemeanor child assault charge earlier this month, cannot be reinstated before April 15, 2015.

“The timing of your potential reinstatement will be based on the results of the counseling and treatment program set forth in this decision,” NFL Commissioner Roger Goodell wrote in a letter to Peterson. “Under this two-step approach, the precise length of the suspension will depend on your actions. We are prepared to put in place a program that can help you to succeed, but no program can succeed without your genuine and continuing engagement.”

Goodell’s suspension of Peterson occurred within guidelines established under the NFL’s revamped disciplinary policy regarding domestic violence, changed in August to allow a six-game suspension for first-time offenders and indefinite suspensions for a second offense. Peterson is a first-time offender, but the policy allows the commissioner’s office to levy more severe penalties if presented with “aggravating circumstances,” the NFL said.

Peterson was indicted in Texas in September for beating his 4-year-old son with a tree branch, known as a “switch.” The Vikings placed Peterson on the exempt/commissioner’s permission list ahead of Week 2. In his letter to Peterson, Goodell laid out three reasons for Peterson’s unique penalty, which will extend beyond the final six games of the 2014 season.

“First, the injury was inflicted on a child who was only 4 years old. The difference in size and strength between you and the child is significant, and your actions clearly caused physical injury to the child,” Goodell said. "Second, the repetitive use of a switch in this instance is a functional equivalent of a weapon, particularly in the hands of someone with the strength of an accomplished professional athlete.”

He continued: “Third, you have shown no meaningful remorse for your conduct. When indicted, you acknowledged what you did but said that you would not ‘eliminate whooping my kids’ and defended your conduct in numerous published text messages to the child’s mother. You also said that you felt ‘very confident with my actions because I know my intent.’ These comments raise the serious concern that you do not fully appreciate the seriousness of your conduct, or even worse, that you may feel free to engage in similar conduct in the future.”

The NFL’s collective bargaining agreement allows Peterson to appeal his suspension, much as former Baltimore Ravens running back Ray Rice  earlier this month appealed his suspension over a domestic violence incident in May involving his wife. The NFL Players Association announced Tuesday that Peterson would immediately exercise that right.

“The decision by the NFL to suspend Adrian Peterson is another example of the credibility gap that exists between the agreements they make and the actions they take,” the NFLPA said in a statement. Since Adrian’s legal matter was adjudicated, the NFL has ignored its obligations and attempted to impose a new and arbitrary disciplinary proceeding. … The NFLPA will appeal this suspension and will demand that a neutral arbitrator oversee the appeal.”