Also, the team released running back Davin Meggett from the practice squad.
Vega was promoted from the practice squad on Oct. 18 and made his debut against the Philadelphia Eagles two days later. Vega had two tackles but was also penalized twice for two offside penalties in the fourth quarter. He didn't record a tackle in 18 defensive snaps against the Detroit Lions last week.
Brown, a 2009 second-round pick by the Carolina Panthers, was one of two defensive ends to workout on Monday. Brown last played in a NFL regular season game in 2011. He was in training camp with the Eagles and Lions since then.
There was a thought guard Brian Waters would be placed on injured reserve to make room for Brown. Waters is exploring his options regarding a triceps injury that owner/general manager Jerry Jones said will probably cost him the season.