PHILADELPHIA- The NFL will ask a federal appeals court in Philadelphia to uphold a potential $1 billion plan to settle thousands of concussion lawsuits filed by former players.
    
Critics appealing the settlement say it compensates some retirees at the expense of others.
    
The awards could reach several million dollars for men with Alzheimer's disease, advanced dementia and a few other illnesses. But it doesn't cover depression, seizures and other disorders that some experts link to concussions.
    
The plan approved by a judge last year would cover more than 20,000 NFL retirees for the next 65 years.  The lead negotiators say the players would have had a tough time proving their case in court.
    
The appeal will be heard Thursday morning in the 3rd U.S. Circuit Court of Appeals.