Sports attorney David Cornwell told the Philadelphia Daily News Wednesday that Hanson is accused of taking a diuretic before last season's NFC Championship Game, a 32-25 loss to the Arizona Cardinals.
Cornwell said Hanson felt "bloated" after eating Chinese food before the contest and later tested positive after taking a pill that turned out to be a diuretic.
The substance was not identified in an NFL statement.
"Joselio did not use steroids or any other substance that would enhance his performance," Cornwell told the newspaper Wednesday.
"Look at (Jose), man," teammate Sheldon Brown said of the 5-foot-9, 185-pound Hanson. "I'm sick for him ... This is one of the good guys on our team."
Hanson's immediate suspension keeps him off the field until Monday, Dec. 7, when the Eagles play at Atlanta.