Aaron Rodgers sits in the corner of a largely empty Pittsburgh Steelers locker room on a random afternoon late in training camp. The four-time MVP stands up and walks over to a nearby trash can, which just so happens to be in front of rookie defensive tackle Yahya Black’s stall. Rodgers turns toward Black — who turned 3 two days before Rodgers was drafted by the Green Bay Packers in the first round 20 years ago — and starts to chat. Mason McCormick, who grew up as a zero-star recruit in South Dakota and will spend this season starting at right guard on an offensive line tasked with protecting a 41-year-old quarterback who doesn’t move as he used to, lumbers by.