ESPN NFL

IRVING, Texas -- The Dallas Cowboys released running back Anthony Thomas on Tuesday and placed linebacker Al Singleton on injured reserve, ending his season.

Thomas, signed in the offseason to provide depth behind starter Julius Jones, became expendable with the emergence of rookies Marion Barber and Tyson Thompson. He had two 1,000-yard seasons in four years with Chicago before signing a one-year deal with the Cowboys.

Thompson caught the attention of coach Bill Parcells with a strong training camp and preseason. Barber has 222 yards and two touchdowns in two games as a replacement for Jones, who is battling an ankle injury. Thompson, an undrafted free agent, is the first Irving native to play for the Cowboys, and Barber is a fourth-round pick out of Minnesota.

Singleton broke a collarbone in Sunday's 34-13 victory against Arizona.

The Cowboys also placed defensive end Jay Ratliff (ankle) on injured reserve, and they signed safeties Tony Dixon and Lynn Scott, both former Cowboys.

Copyright 2005 by The Associated Press