Raiders safety Michael Huff's contract is expected to allow him to become a free agent. A little-known rule prevented Oakland from re-signing Huff this past season, as much as they would have liked to, according to an NFL source. Any player whose salary escalated at a higher rate than 30 percent from 2009 to 2010, as Huff's and other players' did, was precluded from signing a contract extension with his team.