Allen started the first two games of the season before he was replaced by rookie J.J. Wilcox prior to the Sept. 22 win against the St. Louis Rams. In the season opener against the New York Giants, Allen was credited with 17 tackles, two pass deflections and an interception.
The Cowboys have not decided how to fill the roster spot.
Allen was signed to a one-year deal worth $840,000, the veteran minimum salary. He received a signing bonus of $65,000, and $555,000 of his base salary was guaranteed. Allen played for defensive coordinator Monte Kiffin and special-teams coordinator Rich Bisaccia in Tampa Bay and was viewed as a solid locker-room presence.
The Cowboys have four safeties on the roster: Barry Church, Wilcox, Danny McCray and undrafted rookie Jeff Heath. Church suffered a broken nose in Sunday's loss to the Denver Broncos but will not miss a game.