The Raiders plan to release tight end Kevin Boss just one year into a four-year contract. Boss' agent, Scott Smith, tweeted Monday night that the Raiders told him Boss will be released Tuesday and become an unrestricted free agent. ESPN NFL Insider Adam Schefter reported the deal earlier. Boss signed a $16M, four-year contract last summer to replace tight end Zach Miller. The deal included $6M guaranteed, including $4M in 2011 and $2M in 2012, a league source told Schefter.