When a recent study conducted for the NFL suggested that retired pro football players may have a higher rate than normal of Alzheimer's disease or other memory afflictions, the NFL was quick to point out that the study did not prove a link between concussions and memory disorders.

NFL Commissioner Roger Goodell was to tell Congress on Wednesday that while the research by the University of Michigan was "a telephone survey and not a true medical diagnosis," the number of players reporting memory-related problems is a concern. In written testimony to the House Judiciary Committee, he said the NFL will offer free follow-up medical work to 56 players who reported dementia, Alzheimer's disease or other memory-related problems in the survey.

Goodell said the league also will reach out to the players to see whether they are receiving money from the 88 Plan, which provides up to $88,000 a year to former players suffering from dementia, Alzheimer's or Parkinson's, regardless of the cause. A copy of Goodell's testimony was obtained late Tuesday by The Associated Press.

The study's lead author, David Weir, who is among the witnesses for Wednesday's hearing, has said the results show the topic is worth further study but they do not prove a link between playing football and later mental troubles.

"We have directed Dr. Weir to contact in a confidential manner those 56 former players and their families who reported memory problems to see if they are receiving 88 Plan funding and offer them the opportunity to have follow-up medical work done at our expense," Goodell said. "That process has already begun."

Goodell said the health and welfare of all members of the "NFL family, particularly our retired players," is important to him. "Since becoming commissioner, I can think of no single issue to which I have devoted as much time and attention."

As for head injuries specifically, he said medical considerations must always trump competitive ones, and that the league has established a toll-free hot line for players if they believe they're being pressured to return to the field before fully recovering from a concussion or other head injury.

"All return-to-play decisions are made by doctors and doctors only," the commissioner said. "The decision to return to the game is not made by coaches. Not by players. Not by teammates."

He also pointed to changes in rules aimed at reducing contact to the head and neck, the development of improved helmets, research and education.

The new head of the NFL Players Association, DeMaurice Smith, said in his prepared remarks, also obtained by the AP, that the union "has not done its best in this area. We will do better."

But he also criticized the NFL for diminishing studies that showed a connection between football injuries and post-career mental illness. Smith promised that the union's new concussion and traumatic brain injury committee will act as a "superconductor to commission, evaluate, follow and disseminate ongoing research."

On Tuesday, Smith told reporters that while his union has differences with the NFL over how to address head injuries suffered during football games, "This is not a battle between us and the league." He also credited the NFL for doing a "tremendous job" to improve player safety in the past five years.

Other witnesses expected to testify included Rep. Bill Pascrell, a New Jersey Democrat and co-chairman of the Congressional Brain Injury Task Force; medical experts and former players, including former New York Giants running back Tiki Barber.

Among the medical experts on the witness list are researchers from the Boston University School of Medicine's Center for the Study of Traumatic Encephalopathy, who announced last week that a football player who never competed beyond the college level suffered from a degenerative brain disease previously discovered in former NFL players.

It was the first time an advanced case of chronic traumatic encephalopathy was found in a player who did not advance past the college game, suggesting athletes could be at risk for CTE even if they don't play professionally. CTE, originally found in boxers, is caused by repetitive trauma to the brain, with similar symptoms to Alzheimer's disease.

Chris Nowinski, co-director of the Boston University center, planned to make a series of proposals at Wednesday's hearing, "to save football." Nowinski, a defensive tackle at Harvard University and former professional wrestler, suffered six concussions that he "can remember" between the ages of 19 and 23.

The proposals will be focused on youth, high school and college sports.