The Diamondbacks continue to look for depth in the outfield. Pollock may be susceptible to injury, and he will be a free agent at the end of this season. A wise choice would be to acquire depth in center field.
Center fielders who are free agents or rumored to be available via trade include: Aaron Altherr, Keon Broxton, Cameron Maybin, Rajai Davis, Jarrod Dyson, Jon Jay, Tyler Naquin, Brandon Nimmo, Brett Phillips, Ben Revere, Domingo Santana, and Nick Williams.
First, I narrowed my list by removing 6 players with the worst defense in 2017 (as measured by UZR/150).