Former Panthers linebacker Dan Morgan has retired.  Morgan spent seven injury-riddled seasons with the Panthers before signing with the New Orleans Saints in the offseason.  The 29-year-old Morgan played in only three games last season because of an Achilles tendon injury.  He missed all but one game of the 2006 season after suffering the fifth concussion of his career.  Morgan was Carolina’s first-round draft choice in 2001 and made the Pro Bowl in the 2004 season.  His 452 career tackles are the third-most in team history.  The Panthers also signed quarterback Lester Ricard.  The former Tulane star spent last season on Jacksonville’s practice squad.