If Davis is there at 20, Steelers really should take him. Heyward, Davis, maybe Tuitt, Watt, Highsmith, Jack and the other ILB will dominate opposing running games.
I don't think he makes it to 20 so time for Plan B. That plan should be Travis Jones - Connecticut. 6'4", 326 lbs. 34" arms that he uses really well to bat down blocker's hands. Highlights of his Senior Bowl 1-on-1 battles. He is mainly in the 1 tech, a couple times the 2. Uses bull rush and swim move and absolutely dominates time after time. Yes, NFL centers are going to be better, but the way he is tossing around Senior Bowl centers means he has the strength and technique to be a huge problem for opposing teams.
So, defenses, you face Heyward, Davis or Jones, Tuitt, Watt and Highsmith. Who you double-teaming? Oh, I guess that triple team on Watt is no longer an option.