Junior Seau, one of the best linebackers of his era, will announce his retirment on Monday at the San Diego Chargers' training facility, the San Diego Union-Tribune reported. Seau, who spent most of his career with the Chargers, will end his 16-year career with 12 Pro Bowl selections and 1,585 tackles -- the most ever by a linebacker. He's widely considered a lock for enshrinement in the Pro Football Hall of Fame when he becomes eligible in 2011.