Kimbrel and Simmons are the obvious choices. I don't miss Heyward at all. Justin Upton is the guy I miss the most though. Streaky and frustrating hitter to watch, but the power threat was nice to have for once.
I think that's why I'm so high on Kemp. Just the thought of a power threat can be stressful for pitchers and will allow Freeman to get some better pitches to hit.