Adrian Peterson formally filed an appeal through the NFL Players Association in hopes of reducing or eliminating a season-ending suspension levied by the league on Tuesday.

Peterson will reportedly argue that he was not granted due process or an objective hearing as outlined under the collective bargaining agreement. Under terms of the CBA, commissioner Roger Goodell would hear the appeal or assign a proxy.

In its official appeal, the NFLPA requested Goodell recuse himself from upcoming hearings related to Peterson. In a letter to players, the NFLPA claims of Goodell “it is clear that you have, by your actions, rendered yourself evidently partial and biased in this matter.”

The NFL suspended Peterson for at least the rest of the season and gave the 29-year-old former All-Pro detailed protocol for returning to an active role.

The union also wants NFL executive vice president Troy Vincent’s statement to Peterson about being credited for time served to be reviewed. Vincent told USA Today the context of those comments is not being portrayed accurately, and was dependent upon Peterson appearing at a meeting Friday that he chose to skip.

A union-led grievance that sought to clear Peterson to return while the appeal is pending was denied by arbitrator Shyam Das on Tuesday night. Das ruled that the NFL could keep Peterson on the commissioner’s exempt list through the remainder of the year, unrelated to the suspension issued Tuesday. The verdict essentially ends Peterson’s hopes of playing again in 2014.

Before Tuesday, Peterson was on the commissioner’s exempt list, drawing his full salary. The unpaid suspension will cost him approximately $703,125 per week — a total of $4,218,750 — through the end of the regular season.

The NFL stated that Peterson’s suspension comes as a result of “an incident of abusive discipline that he inflicted on his four-year-old son.” Peterson settled the legal matter in a Texas court when he pleaded no contest to a lesser charge of misdemeanor reckless assault earlier this month. He was indicted in September on a felony charge of injury to a child for using a wooden switch to discipline his son.

Goodell wrote in letter to Peterson, from which excerpts were used in Tuesday’s NFL statement, that Peterson does not “fully appreciate the seriousness of his conduct.”

“You have shown no meaningful remorse for your conduct,” Goodell’s letter said. “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.'”

The NFL enhanced its policy for punishing players involved in domestic violence incidents in August. The union in its appeal will argue that Peterson should not be subject to those penalties, which call for a minimum six-game suspension for first-time offenders, because the incident involving his son took place before the disciplinary changes were introduced.

Peterson signed a $100 million contract on Sept. 10, 2011. That deal included $36 million in guaranteed money — a total that has been completely paid by the Vikings. It is growing more likely the franchise will distance itself from the All-Pro running back.

“The NFL has informed the Vikings of today’s decision regarding Adrian Peterson. We respect the league’s decision and will have no further comment at this time,” the Vikings said Tuesday in a statement.

The NFLPA charged that the league is losing credibility by making “arbitrary” decisions on personnel conduct matters.

“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 statement said. “Since Adrian’s legal matter was adjudicated, the NFL has ignored their obligations and attempted to impose a new and arbitrary disciplinary proceeding.

“The facts are that Adrian has asked for a meeting with Roger Goodell, the discipline imposed is inconsistent and an NFL executive told Adrian that his time on the Commissioner’s list would be considered as time served. The NFLPA will appeal this suspension and will demand that a neutral arbitrator oversee the appeal. We call on the NFL Management Council to show our players and our sponsors leadership by committing to collective bargaining so a fair personal conduct policy can be implemented as quickly as possible.”

Peterson’s son suffered wounds to his thigh, buttocks and one of his testicles according to court records reviewed by the NFL.

“The difference in size and strength between you and the child is significant, and your actions clearly caused physical injury to the child,” Goodell’s letter said. “While an adult may have a number of options when confronted with abuse — to flee, to fight back, or to seek help from law enforcement — none of those options is realistically available to a four-year-old child.

“Further, the injury inflicted on your son includes the emotional and psychological trauma to a young child who suffers criminal physical abuse at the hands of his father.”