Minnesota Vikings running back Alexander Mattison has made a solid impression in his rookie season, but he can't be trusted as a starting fantasy option with his current role in the offense. Mattison received just three carries and gained five yards in Week 12's close contest against the Broncos. He just doesn't see enough action in competitive games, and Week 13's road matchup with the Seahawks projects to be a tight matchup. Mattison remains a must-handcuff to Cook, but he isn't likely to ...