Veteran defensive tackle Grady Jackson, one of the few starting-caliber players remaining in free agency just a month before training camps open, will visit later this week with Raiders officials as he seeks a new team for the 2006 season. Jackson, who played for the Packers the past three years, is coming off one of the most productive seasons of his nine-year league tenure, having started all 16 games in 2005, when he registered a career-best 72 tackles. Despite his performance, the Packers made little effort to re-sign Jackson once he entered the unrestricted free-agent market.