The NFLPA was first notified of and invited to join the appeal on August 31. The NFL was notified of Pryor's intent to appeal on August 26.
The Raiders selected Pryor in the third round of the NFL supplemental draft on August 22 and are in favor of the appeal in hopes of, at the very least, reducing the current restrictions on Pryor, according to a league source.
The union will likely file the appeal Monday, according to The Associated Press. The Raiders open the season that night at Denver. Under terms of the suspension, Pryor can't practice or play until the week of Oct. 10.
Concerns from veteran players and agents over the NFL enforcing NCAA penalties are the driving force behind the appeal at this point, with the concern that a dangerous precedent could be set. Pryor was suspended for the first five games of the 2011 college season by the NCAA in December for accepting improper benefits and selling awards had he returned to Ohio State. It's a penalty that might seem to mirror the NFL's punishment, though the league's contention has been that the two are not directly related.
Pryor gave up his final season of eligibility at Ohio State after an investigation into the team's memorabilia-for-cash scandal. He originally was barred from entering the supplemental draft, then was approved by Goodell with the proviso he must sit out five games.
Pryor's coach at Ohio State, Jim Tressel, was also set to serve a five-game NCAA suspension at the beginning of the 2011 season before resigning on Memorial Day, which led to Pryor leaving school to pursue an NFL career. Tressel has since been hired by the Indianapolis Colts as a game-day consultant. The team announced Monday that Tressel's employment as a game-day consultant won't begin until the team's seventh regular-season game.
NFL Commissioner Roger Goodell said the league would have suspended Tressel had the Colts not delayed his start date, but the position of veteran players and agents is that the NFL shouldn't be involved in NCAA punishments in either case.
The process of Pryor gaining eligibility for the supplemental draft was handled over the first two weeks of August, primarily handled between the quarterback's camp and the commissioner's office. The decision to suspend Pryor for five games was Goodell's, with the player's right to appeal written into the verdict. One facet of the commissioner's ruling that Pryor's camp fought hard for was his right to be at his new team's facility and participate in meetings -- a condition that was granted.
The Associated Press contributed to this report