IRVING, Texas -- The Dallas Cowboys on Friday cut veteran cornerback Bryant Westbrook, who had been demoted to part-time starter after committing costly penalties in last week's loss to the expansion Houston Texans.

The Cowboys said Westbrook, who at one point during the 19-10 loss to the Texans was yanked off the field so coaches could talk to him, had lost confidence.

"We've been hanging in there with him,'' Cowboys vice president Stephen Jones said on the team's Web site. "It's not like we didn't have a lot of patience. And then he had a tough week of practice, too.''

Westbrook was called for a 43-yard pass interference penalty on the first play from scrimmage Sunday. He was later called for illegal contact, wiping out a Cowboys sack and giving the Texans a first down.

Cowboys coaches said this week that the 6-foot, 201-pound Westbrook would play on running downs at left cornerback and Duane Hawthorne would come in for passing situations. Hawthorne will now start his 12th career game Sunday against the Tennessee Titans.

Westbrook, a former University of Texas star who played five seasons with the Detroit Lions, signed a one-year deal with the Cowboys after he was released by the Lions following last season.

Because of his six years experience, Westbrook is considered a "vested'' veteran, meaning his entire $875,000 salary is guaranteed and will count against the salary cap.

The Cowboys filled the roster spot by activating linebacker Louis Mackey from the practice squad.