Barkley signed with the Cardinals last November after Drew Stanton was injured, though he didn't appear in a game.
Despite being unable to stick in a single destination for long, Barkley did show some promise when he was the Bears' starting quarterback for six games in 2016.
Per Pro Football Focus, Barkley ranked second among all quarterbacks in average depth per target with the Bears.
Barkley's overall numbers with the Bears in 2016 left something to be desired. He finished with eight touchdowns and 14 interceptions, so cutting down on the turnovers has to be a point of emphasis heading into this next chapter of his career.
At 27 years old, Barkley is no longer able to get by on his potential. He's been given multiple chances to prove himself at least as a viable backup, but he hasn't taken advantage of the opportunity.
The Bengals are giving Barkley another chance to show off his skills. He's accustomed to coming off the bench if his number gets called, so given the low cost, there is really no downside for the Bengals at this point.