By Andrew Gould After taking third-string reps behind Mitchell Trubisky and Mason Rudolph in training camp, Kenny Pickett moved up to the second team during Monday’s practice. Observers itching for clues to solve the Pittsburgh Steelers’ quarterback depth chart jumped to conclusions, but Mike Tomlin downplayed the change. When speaking to reporters, per the team’s practice report (h/t Pro Football Talk), the head coach said he’s just mixing up the groupings to get players acclimated with everyone. “There will be more of that,” Tomlin said. “All of those guys are running in all groups, it’s jus…