Frederick participated in a padded practice Tuesday for the first time since being diagnosed with Guillain-Barre Syndrome last August, David Helman of DallasCowboys.com reports.
He's still being held out of one-on-one drills, largely due to offseason shoulder surgery, but this is a huge step forward in the center's recovery from the autoimmune disorder. Frederick remains on track to start in Week 1 and help the Dallas offensive line return to the dominant form it lost while he was sidelined last season.