The Jacksonville Jaguars have released veteran offensive tackle Jordan Blackfrom the roster, and signed first-year center Bradley Vierling to a 2011 contract.Black joined the Jaguars in 2008 and played in 25 games, including 15 games in 2010 with nine starts.  He was originally a fifth-round draft pick of the Kansas City Chiefs in 2003 and has also spent time with the Houston Texans. Vierling spent the 2010 season on the Jaguars practice squad after signing on Sept. 6. Vierling played in the last preseason game for the Jaguars.