Rep holds a new impact absorbing helmet at the NFL HQ in NY

The clock is ticking for former NFL players to register to access benefits under a historic $1 billion settlement with the league over concerns surrounding the long-term effects of head trauma.

While roughly 20,000 former players are eligible to register before the Aug. 7 deadline, more than 150 former players or their families have opted out of the settlement. However, there is still an opportunity for those who opted out to opt back in.

Those who have opted out of the settlement are allowed to send a written request to the Claims Administrator.

“The Claims Administrator will present your request to Co-Lead Class Counsel and the NFL Parties for their consideration,” the official NFL settlement site says. “If they consent, they will submit your request to the Court for approval.”

The 132 former players — along with 19 relatives of retired players — that have opted out of the settlement are allowed to pursue their own litigation against the league. According to former Buffalo Bills defensive back Jeff Nixon, the reasons for the opt-outs vary widely.

“I have spoken to a few of the players that opted out and I was surprised to find that several were not planning on continuing their litigation against the NFL,” Nixon wrote in a blog post. “Their reason for opting out was purely a political statement. They did not like the terms of the Settlement and wanted to show their disapproval by opting out. While it is admirable that some former players took this dramatic step, I would recommend that they re-think their decision.”

CTE Coverage in NFL Settlement Remains a Concern

Throughout the debate over how the NFL handles concussions and what it will cover, concerns over chronic traumatic encephalopathy (CTE) remained prominent. CTE is a progressive degenerative brain disease caused by repeated blows to the head that leads to a range of symptoms

Symptoms of CTE include disorientation, memory loss, erratic behavior, suicidal thoughts, dementia and more.

“Many of the players that chose to opt out of the Settlement were concerned that it would not cover all players that are diagnosed with CTE in a post-mortem autopsy,” Nixon wrote. “There were also concerns that some of the mood and behavioral problems that are often associated with symptoms of CTE would not be covered.”

A contingent of players asked a panel of appeals court judges to reconsider the settlement over concerns about how CTE is treated in the settlement. Only families of players who died between 2006 and April 2015 and were diagnosed with CTE are eligible to receive a monetary award.

A judge let the settlement stand despite the pleas.

“This settlement will provide nearly $1 billion in value to the class of retired players,” Third Circuit Judge Thomas L. Ambro wrote at the time. “It is a testament to the players, researchers, and advocates who have worked to expose the true human costs of a sport so many love. Though not perfect, it is fair.”

Scientists have focused on learning more about CTE over the past few years. Although CTE remains only confirmed via autopsy, new technology is getting closer to detecting the disease in living people.

According to Nixon, the new technology could be important to retired players currently living with CTE but cannot confirm it.

“The Settlement mandates that the NFL and our attorneys meet once every ten years to discuss in good faith possible modifications to the definitions of Qualifying Diagnoses and/or the protocols for making Qualifying Diagnoses, in light of generally accepted advances in medical science,” he wrote.

He argues that the agreement could change in the future in light of new discoveries to broaden the qualifying terms.

Opt Out Revoke Request Isn’t Guaranteed

While those who have opted out can ask to opt back in, it is not a guarantee that the court would allow it. But, Nixon said it was likely U.S. District Judge Anita Brody, who is in charge of overseeing the settlement, would allow players back in.

“In closing, I would find it hard to believe that Judge Brody would not allow players to opt back into the Settlement, especially when you consider the possibility that cognitive impairments may have clouded some of the player’s judgement,” Nixon wrote.

He also added, “I’m not trying to say that everyone that opted out was not thinking clearly, but it’s not a far stretch to think that it could have been a factor, or played a role in why some players chose to opt out.”

The Aug. 7 deadline is approaching and those who want to opt back are encouraged to send the written revocation to the Claims Administrator as soon as possible. The roughly 20,000 retired players who did opt in are also encouraged to register for benefits before the deadline. As of last month, only about 10,000 former players had signed up.