Eflin was fine last year, except for a one month meltdown which I think was the pitching coach overemphasizing throwing 4 seamers - after that month Eflin went back to emphasizing his 2 seamer and was fine the rest of the way.
July 16.2 29 27 22 5 9 14 11.88 ERA
rest of Season: 146.2 143 61 53 23 39 115 3.25 ERA
He needs tweaks, especially developing his changeup and curve, which have flashed but not been consistent pitches for him. A pitching coach who can sharpen his changeup could take Eflin to the next level.
Velasquez is OK as a 5th starter, but I don't expect more from him.
He's got a plus 4 seamer, a minus curve and an erratic slider.
Which probably makes him more suitable for a bullpen role if the slider becomes more consistent and he junks the curve. The lack of a 2 seamer and changeup limits his potential as a starting pitcher.
Pivetta is sorta the negative image of Velasquez.
Despite its velocity his 4 seamer is a minus pitch (no movement and struggles to locate it)
He has a plus curve but no other decent pitches, hasn't really developed a slider.
Shows you that when looking at pitching prospects, don't put that much emphasis on velocity once a pitcher hits 92+ as an average, movement is more important (see Pivetta and his hittable 95 MPH). Do put emphasis on a young pitcher who is developing at least three credible pitches and has good command. I think if a young pitcher can master 3-4 pitches in the minors at a credible level, a ML pitching coach can refine them, but if he struggles to pick up different grips and maintain a consistent delivery, he may not be able to make that kind of big jump at the ML level.
Which is why Seabold is my dark horse candidate, he's gradually improved his velo to 91-95, has also improved his secondary offerings and has above average command. Was solid at Reading and in the AFL and should start the year in LHV with Howard. Not saying he'll be a top of the rotation guy, but could be a reliable innings eater at the back of the rotation - which is what this team needs in a #5.