Vikings training camp position preview: Running backs

When healthy, Cook is one of the NFL's top two or three backs and the rare case of a player at his position being worth the five-year, $63 million deal he signed last September. Cook's response to that mega deal was career highs in carries (312), yards (1,557), touchdowns (16) and average (5.0). He also extended his streak of 40-catch seasons to three, continuing his stretch as one of the more versatile weapons in football. Although he's played in 30 of 34 games the past two seasons, Cook still has not played a full NFL season. The new 17-game schedule and perhaps a more cautious workload for Cook in 2021 should create more opportunities for Mattison, a solid backup with age (23), energy and fresh legs (196 carries in two seasons) on his side. Ham, who turns 28 on Thursday, enters his fifth NFL season in his prime as one of the league's more reliable fullbacks.

Can Cook stay healthy? Like most backs not named Derrick Henry, Cook will always face questions about his health from week to week, especially in this offense. Cook's durability was impressive overall last season. He carried the heaviest of loads as the Vikings went from 1-5 to 6-6. But it's still a fine line the Vikings must walk when it comes to doling out touches for their most important offensive player. They pushed the limits last year and it got them back into playoff contention. But Cook also missed the last 28 minutes of the Seattle game and the following week against Atlanta after getting 21 first-half touches at Seattle. The Vikings lost both games to fall to 1-5.