Of all the free agent quarterbacks available this year, Mike Glennon is my top backup QB option for the Dallas Cowboys in 2017.
If the Tampa Bay Buccaneers hadn't drafted Jameis Winston a couple of years ago, Glennon likely would have remained the starting QB for the Buccaneers. But, that's not how things turned out, which could be good news for the Cowboys.
Glennon is more athletic than his 6'6″, 225-pound frame would indicate, which means the Cowboys offense wouldn't have to change very much if he had to step in for Prescott. He has the ability to execute the hard play fakes and bootleg plays outside of the pocket. His arm strength isn't as strong as you might expect for a QB of his size, but he's capable of throwing the ball down the field with ease and accuracy. Glennon is at his best throwing short to intermediate routes and is more than capable of fitting passes into tight windows.
Now, Mike Glennon is probably looking for a chance to be a starter somewhere, but he may be willing to accept a backup role on a short-term contract. It's unlikely Glennon would accept a backup role with the Cowboys when he can probably get the same kind offer to remain in Tampa Bay — where he currently resides — but the Cowboys would be wise to at least see if he is interested.