Hanson's attorney, David Cornwell, said in a statement that Hanson did not use steroids but tested positive for a diuretic after last year's NFC title game against Arizona.
"The urine specimen that Joselio provided after the game tested positive for a diuretic," Cornwell said. "Joselio did not use steroids or any other substance that would enhance his performance."
While not specifying what product Hanson used, Cornwell said the player "felt 'bloated' after eating Chinese food and ingested a pill that turned out to be a diuretic."
Cornwell said the NFL's policy on diuretics is misguided because it assumes they are used to mask the use of performance-enhancing drugs.
"It is noteworthy that the World Anti-Doping Agency recently implemented amendments that eviscerate the misplaced presumption about diuretics embedded in the NFL's steroid policy and reduce discipline for diuretics to include warnings and, where appropriate, suspension."
Cornwell said he had hoped the league would delay making a decision on Hanson until there was a resolution in another case involving four players who have suspensions pending for taking a banned diuretic.
Two Minnesota Vikings, Kevin Williams and Pat Williams -- who are not related -- tested positive in 2008 for the diuretic bumetanide, which is banned by the NFL because of its masking capabilities. The players acknowledged taking the over-the-counter weight loss supplement StarCaps, which did not state on the label that it contained bumetanide. Neither player is accused of taking steroids.
The NFL issued four-game suspensions, but both players sued the NFL in state court, arguing the league's testing violated Minnesota laws. The case was moved to federal court, and the NFL players union filed a similar lawsuit on behalf of the Williamses and two New Orleans Saints players also suspended.
In May, a federal judge dismissed the union's lawsuit and several claims in the Williamses' case but sent two claims involving Minnesota workplace laws back to state court. A judge there issued an injunction prohibiting the NFL from suspending the players and has scheduled the trial for March.
"We also argued that the accommodation allowing the 'StarCaps players' to continue playing supported allowing Joselio to continue playing as well," Cornwell said in his statement. "Our appeal to fairness was rejected."
Another Eagles cornerback, Sheldon Brown, said Wednesday he thinks Hanson is being treated differently than the other players.
"It seems like they're trying to make an example out of somebody so it can't keep continuing to happen," Brown said. "From what I know of Hanson, I don't think it's fair, because he's a class act."
Hanson has recorded 29 tackles and one interception this season as a backup to starters Asante Samuel and Brown.
Hanson's suspension came the same day the Eagles placed cornerback and kick returner Ellis Hobbs in injured reserve with a neck injury. Hobbs will require surgery but Eagles coach Andy Reid expects the injury is not career-threatening. Hobbs recorded 14 tackles and averaged 24.1 yards on 20 kickoff returns this season.
To replace Hanson and Hobbs, the Eagles promoted second-year cornerback Jack Ikegwuonu from the practice squad and signed free agent Ramzee Robinson, who was among the Detroit's final cuts in September. The Eagles also added cornerback Stoney Woodson to the practice squad.