Why injuries like Aaron Rodgers' make the backup QB essential

On Dec. 4, 2022, quarterback Josh Johnson, then a member of the Denver Broncos' practice squad, was traveling home with the team after a road game in Baltimore.

"One of my teammates was sitting next to me and told me Jimmy [Garoppolo] got hurt," Johnson told ESPN. "He was like, 'You about to go to the Niners, bro.' And I'm like, 'Man, hell no.'"

Nearly 2,500 miles away, on the opening drive against the Miami Dolphins, Garoppolo, the starter for the San Francisco 49ers at the time, was carted off the field. His team was suddenly razor thin at quarterback while fighting for top seed in the NFC heading into Week 14.

Sure enough, Johnson got a text from his agent, Doug Hendrickson, on that flight.

"…