6. Matt Ryan (Free agency)
I will start this by saying that I fully believe Matt Ryan will retire after he has cashed his final checks from the Colts. He seems to be content with being a CBS analyst and hasn't shown much intention to get back on the field.
However, if he were to have that want to play again then Arthur Smith should call him up and run it back. Ryan would finally have a decent defense on the other side and a good running game. The veteran knowledge of Ryan would allow him to be a distributor rather than a playmaker for this offense.
I could see the Falcons having a lot of success with Matt Ryan under center again.