Vikings add depth in signing LB Mitchell

EDEN PRAIRIE, Minn. With only four linebackers returning, the Minnesota Vikings added some depth to the position on Tuesday. According to the team's website, Minnesota signed Marvin Mitchell, a five-year veteran who played last season with the Miami Dolphins. Mitchell, 27, will also play on special teams after tallying 30 tackles, one sack, one interception and one forced fumble last season with Miami, while also leading the team with 12 special teams tackles. Mitchell, a seventh-round pick by the New Orleans Saints in the 2007 draft, has 119 career tackles and two sacks. He's started two of his 71 career games and had a career-high 43 tackles in 2010 with New Orleans. He began his career on the Saints' practice squad before being added to the active roster in October of his rookie season. He's played at least 14 games each of the past four years. Starters Chad Greenway and Erin Henderson return to the linebacking corps and will start on the outsides in the Vikings' 4-3 scheme. ...