Mingo, the No. 6 overall pick in April's draft, wasn't expected to miss more than a week, but on Friday, Mary Kay Cabot of The Plain Dealer quoted a noted thoracic surgeon who hadn't treated the rookie as saying the injury is "very, very unusual." The surgeon suggested Mingo would need at least two to three weeks to heal. That would shelve the linebacker for the rest of the preseason and perhaps the Browns' Sept. 8 season opener against the Miami Dolphins.