Austin, who missed a few days of practice last week as well as Sunday's second preseason game against the San Diego Chargers, had returned to practice Tuesday. Austin, however, is still having problems, and team officials decided to keep him out of practice as a precaution.
Kevin Ogletree replaced Austin on the first team in practice Wednesday morning.
Also, backup inside linebacker Kenwin Cummings underwent minor surgery on his right thumb to relieve pressure from a severe bruise. Cummings, who leads the team with nine tackles in the preseason, watched practice while wearing a cast and is day to day.
If Cummings plays in Saturday's third preseason game, against the Minnesota Vikings, he'd most likely keep the cast on.
Calvin Watkins covers the Cowboys for ESPNDallas.com. Information from ESPNDallas.com's Todd Archer contributed to this report.