Kiley McDaniel has his top 200 prospects over at FanGraphs. A's representation is as poor as you'd expect: Franklin Barreto is the only player to get a writeup (the top 142, a/k/a the players with a 50 (average) "future value" rating, get writeups) while Matt Olson, Renato Nunez, and Matt Chapman are all listed as 45 "future value" players and therefore unranked specifically but in the 143-to-200 range.

McDaniel sees Barreto as a possible utility guy if he needs to be that and, perhaps most importantly for the A's, a fast mover despite his youth because of advanced hitting skills. He sees two future plus tools, but they're his speed and arm, so you can see why he doesn't rank higher.