Procter started only 13 games in five seasons with the Cowboys. Eleven of those starts came at left guard in 2008 for injured Kyle Kosier.
The Cowboys originally signed Procter from the Detroit Lions practice squad in November 2005.
Montrae Holland, a guard who was the team's only unrestricted free agent, got a new two-year contract this offseason. Though Holland was expected to become the backup center, coach Wade Phillps said Monday that Kosier would likely fill that role instead.
Procter wasn't part of the team's first organized team activities of the offseason Monday.