Stringer collapsed from heatstroke later that day, and died the next morning.
The NFL discouraged the use of ephedra when Stringer played and banned the substance after he died.
The supplement has been linked to heart attacks, strokes and seizures in otherwise healthy young people. Studies show it also interferes with the body's ability to avoid overheating.
O'Neal said the timing of the filing had nothing to do with last week's death of Baltimore Orioles pitching prospect Steve Bechler in Florida, where a medical examiner has said the death may have been linked to an ephedra-based diet pill.
Court records show a bottle of Ripped Fuel, which contains ephedra, was found in Stringer's locker on the day he collapsed.
Toxicological tests of Stringer's body found no trace of ephedra, although it did find caffeine, another chemical in Ripped Fuel.
* Jimmy Gould, the agent for Green Bay wide receiver Terry Glenn, said the Packers have granted their request to seek a trade to another team.
* Baltimore signed guard Edwin Mulitalo to a 7-year contract.
* Sports memorabilia dealer Michael Bertolini has been ordered by a New York state judge to pay $105,000 to Indianapolis quarterback Peyton Manning for autographing 2,500 items, including footballs, helmets and jerseys. *