CLARENCE E. HILL Jr. Linebacker Bobby Carpenters days as a Dallas Cowboy might be coming to an end.The Cowboys are in talks with the St. Louis Rams about trading Carpenter for tackle Alex Barron in what essentially would be swapping two first-round draft disappointments. Barron would have to sign his $2.62 restricted free-agent tender to make the deal happen, which could be in the next few days.Carpenter confirmed Thursday that talks have been going on for about a week.Carpenter has started just one game since being picked 18th overall in the 2006 NFL Draft.