The 6-foot-3, 180 pound righthander probably should have been taken before the sixth round, if not for a drop in velocity. He's got a big frame (you can see a similarity between all the Astros drafted pitchers) and could probably fill out some more. I don't get the sense that his delivery is repeatable. It's not max-effort, but he does whip his arm towards the plate to create torque. It's not a huge, huge deal, but it's the sort of thing that makes me wonder about injuries down the road.
He has two good pitches, a curve and a change (where have I heard that before), but they are more effective when he has velocity on the fastball. He also has trouble being consistent with the pitches, and that could be a product of his delivery needing work.
The Astros probably will need to work with him on some things, and hope he can develop the muscle memory to repeat a corrected throwing motion. He's not as ready a prospect as Folty or even Doran, but you can see some potential there.
Obviously, there's always a chance he gets hurt. If he can't figure out his delivery issues, he'll also never be consistent enough to make it into the upper minors. I could see him moving into the bullpen and trying to rely on his curve as an out pitch to generate ground balls.
If he gains some velocity back, he can be a back-end starter. I don't know that his secondary pitches will ever be good enough to be higher than that, but he's got good potential. I get the feeling he's one of those arms that the Astros liked in their private workout, so Plutko could surprise people in the next year. Remember, both Seaton and Lyles had drops and/or injury concerns before the draft.
Will the Astros Sign Him?
The biggest obstacle here will be his commitment to UCLA. Plutko needs a good deal of work and the Astros may not be willing to pay him what he wants to avoid going to college. In the sixth round, there is some benefit to him going to school and trying to move up into the first couple of rounds. At the same time, the Astros do have some money stashed and could work something out.