Third-year guard Kevin Kowalski will be out at least two weeks with a leg injury, so he will miss playing in the first two preseason games.
Kowalski came out of Tuesday's practice. He had been playing with the first unit until the return of starter Nate Livings and backup Ron Leary this week.
Kowalski's absence now leaves the Cowboys with two linemen sidelined. Mackenzy Bernadeau, the starting right guard, is recovering from shoulder surgery in the offseason. Offensive line coach Bill Callahan said he was optimistic that Bernadeau could return next week.