Free agent OGs Rex Hadnot and Antoine Caldwell visited the Patriots on Thursday. It's Hadnot's first visit of free agency, and Caldwell's fourth. Hadnot, 31, started three games for the Chargers in 2012, but he has started 96 career games in his nine-year career. Both players can play all along the interior.

Chargers GM A.J. Smith confirms new G/C Rex Hadnot will push Tyronne Green for the starting left guard job. "(Rex) is coming in to strengthen our backup corps," Smith said. "And he will be in the mix for the open left guard spot ... That's heavy competition right there." Hadnot graded out as one of the league's poorer guards by Pro Football Focus for the Cardinals last season, but did rate better than Green, who made only eight starts. It will be a battle to watch in Bolts camp.

Chargers signed G/C Rex Hadnot to a one-year contract.

The Titans are "monitoring" free agent centers Rex Hadnot and Jamaal Jackson. The Titans hosted Dan Koppen for a free agent visit on Wednesday, and he appears to be the club's first choice. Jackson is going on age 32 and couldn't beat out undersized rookie Jason Kelce for the Eagles' starting job last season. Hadnot, 30, would be a more versatile option with the ability to play guard.

Cardinals released G/C Rex Hadnot.

Coach Ken Whisenhunt indicated that journeymen Rex Hadnot and Jeremy Bridges will duke it out for the right guard job. The Cardinals won't be chasing a veteran free agent to take Deuce Lutui's spot. Hadnot is more than capable of holding down the fort, but the Cardinals have still done little to improve their leaky pass protection.