Petty's MRI on Friday revealed a bruised shoulder with no structural damage, NFL.com reports.
Petty's recovery timetable is uncertain at this point, but coach Todd Bowles said he won't be placed on injured reserve before the Jets make their final cuts. Nonetheless, his injury helped cement Geno Smith as New York's No. 2 quarterback going into the regular season. That being said, Petty showed good strides in his second preseason and could again push for Smith's job once healthy.