The Cowboys signed cornerback Vince Agnew to their practice squad today. To make room on the 8-man practice squad, the Cowboys released cornerback Mario Butler.

Vince Agnew signed with the Miami Dolphins as an undrafted college free agent in July last year. He was signed to and released from the Dolphins practice squad twice in 2011 before signing for the third and final time in November 11. He spent the entire 2012 offseason and training camp with the Dolphins before being released with final cuts on August 31st this year.

Agnew spent his college career at Central Michigan where he was a starter in all 12 games in his final year, ranking fifth on the team in tackles (73) and leading the Chippewas in pass breakups (six).

The former Dolphin replaces Mario Butler, who's had a similar on-again, off-again tenure with the Cowboys. He spent last season on the practice squad, and initially made the 53-man roster and even played against the Giants in the season opener, but was later released and re-signed to the practice squad.

The 5-10, 192 Agnew has intriguing measurables, clocking a 4.38 40-yard dash at his Pro Day. Additional measurables: 39.5 vertical, 11'02' broadjump, 4.18 short shuttle and 6.68 three-cone. But that potential has yet to translate into NFL production. Perhaps the Cowboys will find a way for him to contribute.