Running game

Optimist: Nagy’s decision to fire offensive line coach Harry Hiestand and hire Juan Castillo turns out to be a masterstroke, as a rejuvenated offensive line — with Pro Bowlers Cody Whitehair and Charles Leno and alternate Germain Ifedi — turns David Montgomery into a Kareem Hunt facsimile with 1,200 yards, 4.7 yards per carry and 10 touchdowns. And Cohen finally becomes the feared weapon as a gadget player he looked like he could be in 2017-18.

Pessimist: The offensive line is the biggest victim of the COVID-19 offseason, robbing Castillo of the opportunity to install his scheme and use his ‘‘we’lloutwork-everybody-else’’ strategy. And it shows. Montgomery is just a guy. Cohen is a nonfactor. And a daunting reality hits general manager Ryan Pace: He needs two first-round-caliber offensive tackles.