Travis Frederick's timetable to return to football is still unclear.
Since being diagnosed with Guillain-Barré syndrome last week, the Dallas Cowboys center has worked out with the team and was out watching practice on Tuesday. But NFL Network Insider Ian Rapoport reported that it's too early to tell if Frederick will be placed on injured reserve. The team will make a decision next week whether to do so.
A source told Rapoport that Frederick's recovery could be measured optimistically in weeks, not months. In that case, Frederick could be placed on IR with a designation to return after eight weeks or stay on the active roster until he's ready to return.
With Frederick sidelined, Joe Looney will start at center to open the season.
In other injury news, Cowboys guard Zack Martin returned to practice Tuesday and was seen "moving around well" in individual drills. Martin suffered a hyperextended knee and bone bruise in Dallas' second preseason game.