Byrd (hamstring) didn't practice Thursday, Darren Urban of the Cardinals' official site reports.
Byrd has yet to take the practice field this week, placing a cloud over his availability for Sunday's divisional showdown against the Seahawks. Considering he's received 92 percent of the Cardinals' offensive snaps through three games, Byrd's direct backup (Trent Sherfield) could be on pace for his first significant workload of the campaign.