Cowboys right tackle Doug Free has already been penalized six times this season.
Free, who has four false starts and two holding calls, said Wednesday that he definitely hasn't played up to his potential and needs to keep working at it. He had four penalties in the last game.
Free is in the second year of a four-year deal that guaranteed him $17 million. He started all 32 games over two seasons at left tackle before switching sides this year with Tyron Smith, who as a rookie in 2011 played all 16 games on the right side.
Smith has six false starts, but four came in the opener.
Dallas (2-1) is home Monday night to play Chicago, the NFL's top sacking team.