Mattison has been the subject of trade discussions with "at least 12" teams, according to Chris Tomasson of the St. Paul Pioneer Press.
The 2019 third-round pick is in the final season of his rookie contract and doesn't plan to sign an extension with the Vikings. Mattison isn't likely to get more than 5-to-7 touches per game when the team has Dalvin Cook, who missed multiple contests in each of his first five seasons. Cook's shoulder is particularly vulnerable to re-injury after numerous sprains and dislocations, but he seems to be healthy heading into a Week 1 joust with the Packers.