Lock will back up Kevin Hogan on Thursday in the preseason opener against Atlanta, Zac Stevens of BSN Denver reports.
Lock has reportedly had some of the Broncos quarterbacks' most dazzling highs and head-scratching lows, but is still listed as Denver's No. 3 quarterback. Head coach Vic Fangio has cautioned that, outside the first team, the depth chart is not necessarily indicative of standing, so it's unclear whether Lock has taken a step back in his development, or if the coaching staff is simply making him earn the backup job over the veteran Hogan. The picture will become clearer Thursday as both quarterbacks figure to play against future backups and camp bodies.