Some clinicians tasked with evaluating the eligibility of former NFL players for compensation from the league's landmark 2013 concussion settlement worry that the testing process and protocols discriminate against Black players, an ABC News investigation published Wednesday has found.

The New York Times reported in August that two Black former players -- defensive end Kevin Henry and running back Najeh Davenport -- filed a lawsuit against the NFL, accusing the league of "explicitly and deliberately" discriminating against Black players filing dementia-related claims.

At issue is a process called "race-norming," which has been used by scientists for decades as a way to correct for the lower levels of education often found in minority communities. It was designed to prevent the overdiagnosis of cognitive impairment in these communities, but according to Henry and Davenport's lawsuit, when applied to the NFL concussion settlement, it is having the opposite effect -- making it more difficult for players to show cognitive decline.

When former players file a claim for compensation, they undergo a battery of testing to measure their cognitive functioning. Those scores are compared against a baseline score, or "norm," meant to represent a normal level of cognitive functioning. If the scores fall far enough below that norm, the player is eligible for compensation. But the norm for Black players is lower than the one for white players.

While adjusting for race is not a requirement for clinicians evaluating former players, according to ABC News, the manual outlining testing protocols recommends a "full demographic correction," which includes age, gender and race.

According to ABC's findings, which partly relied on emails from a professional listserv, some clinicians involved in the settlement are now questioning whether the recommendation to adjust for race is, in practice, a requirement.

The clinicians, ABC's investigation found, wrote that the league's protocols superseded their professional judgment, sometimes leading to a "drastically different outcome" for former players seeking help. In the emails reviewed by ABC News:

• One neuropsychologist claimed the league's program manual offered no such flexibility: "I don't think we have the freedom to choose," the clinician wrote. "If we do, apparently many of us have been doing it wrong."

• Another wrote about their possible complicity in a system that perpetuated "racial inequity" in payouts: "Especially in the correct [sic] of our current state of affairs, I'm realizing and feeling regretful for my culpability in this inadvertent systemic racism issue," the clinician wrote. "As a group we could have been better advocates."

• Another contended that while their "required reliance on these norms is spelled out in the manual," it was still up to them to consider the consequences of their compliance: "Bottom line is that the norms do discriminate against Black players," the clinician wrote. "So now what? In this time of reckoning, like many professions, I think we need to look closely at the expected and unexpected ramifications of our practices."

The NFL disputed the findings, saying in a statement that the concussion settlement was "agreed to by all parties, with the assistance of expert neuropsychological clinicians and approved by the courts more than five years ago" and "relied on widely accepted and long-established cognitive tests and scoring methodologies."

"The settlement seeks to provide accurate examinations to retired players," an NFL spokesperson said, "and thus permits, but does not require, independent clinicians to consider race in adjusting retired players' test scores as they would in their typical practice."

The attorney who represented players in the class-action lawsuit that spurred the concussion settlement, Christopher Seeger, issued a statement to ABC News through a spokesperson that called on the court overseeing the administration of the settlement to issue a "clarification" on the issue.

"The use of race-based demographic norms is ultimately left to the clinical judgment of the neuropsychologist and is not mandated by the settlement," Seeger said in the statement. "To the extent that there is any perceived confusion, we would support a clarification from the Court to make it clearer that the use of demographic adjustments, including for race, is not required, and that the neuropsychologist examining a player should use their professional judgment to select the appropriate demographic adjustments to apply to the player's test results."

The NFL Players Association, the labor union representing current and former players, declined to comment.

ABC News reporters Pete Madden, Cho Park and Ryan Smith contributed to this report.