Williams (hamstring) practiced in a limited fashion Thursday, Tommy Yarrish of the Cowboys' official site reports.
Williams was also labeled as limited for Wednesday's walkthrough, so the hamstring issue isn't entirely preventing him from practicing. Still, the veteran defender will likely get tagged with a designation for Sunday's matchup against Arizona if he's not able to upgrade to full participation Friday. Williams has been an important part of the Cowboys' pass rush of late, logging a sack in three of his past four games.