The NFL Players Association, at the request of Trent Williams, decided not to move forward for now on a joint review with the league of the medical treatment given by the Washington Redskins to their seven-time Pro Bowl left tackle.

It is the latest procedural maneuver in the increasingly bitter confrontation between the Redskins and their most accomplished player, who has alleged that team doctors failed for years to take seriously a cancerous growth on his head, leading to his recent five-month holdout.

While this latest back and forth could contribute to the animosity between Williams and the franchise, it is not expected to have a significant impact on the question of whether Williams will play for the team again.

According to a person familiar with the situation, the NFLPA never agreed to participate in the joint review, which would be conducted under the terms of the collective bargaining agreement, despite Friday’s announcement by the league that the review would take place.

NFLPA officials had not spoken to Williams at that point, the person said, and when they did so later Friday, he was adamant that he did not want the NFLPA to participate.

So the union is not proceeding with the review under the CBA at this time, said the person, who spoke on the condition of anonymity to describe a sensitive situation. The union could choose to do so later, even over Williams’s objection, if new information surfaces and the NFLPA believes that the rights of other players must be protected.

It also is conceivable that the league could push for the review to proceed without the consent of Williams and the NFLPA, according to that person. But Williams has the right, if he chooses, to withhold access to his medical records from the medical experts who would be chosen to conduct the review.

DeMaurice Smith, the executive director of the NFLPA, confirmed Williams’s objection to the review in a written statement released after Smith first disclosed Williams’s wishes Monday in a radio appearance on 106.7 the Fan.

“Our union will continue to support Trent,” Smith said in the statement. “Although he has asked us to not pursue a formal review of his treatment, we will consider all legal action if the affirmative disinformation campaign and the leaking of his private medical records does not stop. Doctors have an ethical obligation to treat our men as patients first regardless of where their check comes from. It is our job to ensure that they honor that duty and if we find that they have not, we must then hold the physician accountable to the CBA and their medical licensing authority.”

The Redskins asked for the review this past Thursday, hours after Williams alleged that team doctors failed — for more than five years — to take seriously a growth on his head. This past winter, the growth was diagnosed as a rare form of cancer that Williams said had nearly gone through his skull and into his brain. The cancer, Dermatofibrosarcoma Protuberans, or DFSP, has a 10-year survival rate of 99 percent. But the experience rattled Williams, who said he was told by a doctor to get his affairs in order because of the fact he might die, and underwent three surgical procedures to remove the tumor and repair his skin.

Williams did not return to the Redskins after his surgery, asking to be traded and then holding out for five months.

On Sunday, the NFLPA put out a statement supporting Williams and slamming an NFL Network report by former Redskins general manager Charley Casserly, who is now a contributor for the league-owned network, that said Williams was told by a Redskins doctor to see a specialist about the growth three years ago but never did.

“We are also aware of misinformation being repeated on the NFL’s own network that is not sourced and is only designed to tarnish Trent’s reputation,” the NFLPA’s Sunday statement said, in part. “Our union supports Trent, is protecting his rights and continues to consider potential action if a campaign against him continues.”

None of the recent developments are expected to have much of a practical impact, other than further intensifying emotions, on the question of when or whether Williams will again play for the Redskins. He returned to the team last week, seemingly in an effort to get credit for a year toward free agency, but he did not pass a physical because he was unable to comfortably put a helmet on his head. The team was granted a two-week roster exemption for Williams, after which point it will need to make a roster decision with him.

If Williams continues to fail his physical, the team may have to place him on the non-football injury (NFI) list. If he remains on that list the rest of the season, his contract will probably not toll — meaning his contract status would remain the same and he would still be eligible for unrestricted free agency following the 2020 season.

If Williams does pass his physical, things could grow more complicated. Williams could refuse to play for the team, which could result in team discipline, or if he does return to the field, the Redskins could attempt to toll his contract based on him failing to meet the unofficial threshold of being on the active roster for eight games this season.

Under the joint review, the NFL would have chosen one medical expert, the NFLPA would have chosen another and those two doctors would have selected a third member of the panel. The three-person panel would have conducted the investigation and reviewed Williams’s medical records if he had given permission. The panel would have prepared a report for the NFL and NFLPA.

The Redskins, if found to have committed wrongdoing, would have been subject to possible discipline by the league, likely a fine. The review also is designed to provide information about improving future interactions between players and teams’ medical staffs.

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