"THIS WAS the day's second question-and-answer session for Jack Ikegwuonu. The rookie cornerback was now being quizzed about which Eagle might be slotted for which spot in the nickel and dime packages, with the Birds preparing for Sunday's visit to San Diego.Ikegwuonu acknowledged he wasn't sure."I came in today thinking I'd be on the practice squad," he reminded his questioners.Yesterday was a strange, disruptive day for the secondary, which in a matter of hours, without even putting on pads, went from being the team's deepest unit to one of its biggest question marks. On the same morning Eagles coach Andy Reid announced that corner Ellis Hobbs would have surgery and was done for the season with a neck injury, the team learned Joselio Hanson, the other top reserve at that position, was being suspended without pay for 4 weeks for violating the NFL's policy on performance-enhancing substances.Hobbs, also the Eagles' top kick returner, was injured in Sunday's loss to the Cowboys. Hanson, according to a statement released by sports attorney David Cornwell, took a pill "that turned out to be a diuretic," after feeling bloated from eating Chinese food before last season's NFC Championship Game, and tested positive for that substance. Diuretics can mask the presence of steroids in a urine sample, although Cornwell contended that is seldom the case."Joselio did not use steroids or any other substance that would enhance his performance," Cornwell said.At any rate, the Eagles added corner Ramzee Robinson, cut by the Lions in the preseason, and signed Ikegwuonu from their practice squad. After starters Asante Samuel and Sheldon Brown, the corner with the most experience in their defensive scheme Sunday will be Dimitri Patterson, who returned to practice yesterday after missing a month with quadriceps and hand injuries. Patterson has played three games as an Eagle, all this season, mostly on special teams."