1. Taylor Heinicke
There are few quarterbacks in the league that fit the backup role in Arthur Smith's offense as well as Taylor's will. The backup has had an up-and-down career that was highlighted by giving the eventual Super Bowl champion Bucs all they could handle in a playoff game two seasons ago.
It is hard not to like Heinicke based on the effort and story the quarterback provides. Taylor is mobile enough to run Smith's offense and would be a great point guard in this system. The one obvious flaw in his game is the lack of a deep ball threat. In Atlanta's offense teams are already going to be crowding the line expecting the run having a quarterback that cannot occasionally take advantage of this and push the ball down the field is a concern.
Despite this Heinicke fits Atlanta's offense and has proven to be a capable passer that could push Atlanta into the playoffs if Ridder were to be injured or struggles.
This is Atlanta's likely only answer at the position the other two quarterbacks suggested are only in the case of an injury.