Selvie became a Cowboy when he was brought in off the street during training camp in 2013. The team had a run of injuries at defensive end. At the time, he was thought to be just another camp body. Instead he turned in a surprisingly good 2013 season when he was elevated to starting left defensive end.
In his first year with the Cowboys in 2013, Selvie started every game. He finished second on the team with seven sacks, which was one more than Cowboys all-time sacks leader DeMarcus Ware. Selvie also tied for the team lead in 2013 with seven tackles for loss. He was third on the team with 22 quarterback pressures and had 39 tackles.
In 2014, though, Selvie's play came back to earth and while he was a decent contributor the splash plays were basically gone from his game.
Now that Dallas has Greg Hardy and DeMarcus Lawrence, it's conceivable they might want to flip Jeremy Mincey over to the strong side. This would have made Selvie even more expendable and not in the Cowboys future plans.