There's been something of a vendetta against Appel held by the Astros' fanbase since the pre-draft process last year. Some of it was due to the fact that he was represented by Scott Boras, who seemingly drove a hard bargain with the Astros' management and priced Appel out of the team's strategy. Some of it also seemed to come the perception of Appel as a prospect, however, especially in the preseason this year. However, Appel is not the same pitcher he was at the end of the 2012 campaign- he's a much better one.
Appel has a prototypical pitcher's body- broad shouldered, 6'5", and strong in the lower half. He's a great athlete and he moves very fluidly in his delivery. His arm is loose and he generates good arm speed, but he doesn't have to put a ton of effort into his mechanics to create plus velocity. He takes a long stride and generates good leg drive and his delivery doesn't put much stress on his elbow. As far as his mechanics go, he shouldn't be a big injury risk.
As far as stuff goes, Appel has it all. His fastball is not his best offering, but it's still a 60 pitch on the 20-80 scale. He tends to sit around 95 MPH, but touches as high as 98. His fastball can be a bit true at times, but at its best it has significant arm side run. As he adjusts to pro ball and throwing every fifth day, he'll likely sit 93-96, which will still make his fastball an above average pitch for him to work off of.
Appel's best breaking pitch is his plus slider, which he has learned to command much better this season. He can throw it for strikes and as a chase pitch, and it generates plenty of swings and misses. The pitch has hard velocity, between 86-88 MPH, and it has a sharp cutting action with late bite and is a present plus offering.
In addition to his fastball/slider combo, Appel has developed an outstanding changeup this season. He has learned to command it immaculately, and the bottom absolutely falls out of the pitch as it approaches the plate. It fades away from right-handed hitters, playing excellently off of his fastball. Like his slider, it qualifies as plus and a true out pitch. Appel will also mix in the occasional curveball with decent shape, though it's more of an average, change of pace pitch to round out his arsenal.
Though I see all kinds of tremendous stuff when I watch Appel throw, one thing does concern me. The Stanford coaching staff has shown little concern for his professional future while relying on him as their Friday starter, and his pitch counts have routinely reached levels over 120 or 130 pitches in important games. Though his stuff has not diminished to this point and he's remained remarkably healthy, there's been some significant tax on his arm and that can't be forgotten when evaluating him.
For all the debate about the true quality of Mark Appel as a prospect, I am in the camp that believes he does have the potential to be a #1 starter if he stays healthy like he has to this point. He has two offspeed pitches that can be dominant to pair with his above-average to plus fastball, and his command is above average, as well. He needs to continue to polish his craft and use his changeup more liberally since he primarily throws fastballs and sliders in college. There's very, very little to complain about here.
All that stands between Appel and being anything less than a #2/3 starter is health. He's very polished and already has big league plus stuff.
Right-handed Cliff Lee. 3 phenomenal pitches and command that should continue to improve as he matures.
Projected Draft Round
It seems very unlikely that he slides past pick 2, but if Moran goes #1, he could go between 3-5.
Will he sign?
That shouldn't be a problem this time.
MARK APPEL PROSPECT VIDEO, RHP, STANFORD UNIVERSITY AT USC INNINGS 1-3 (via Steve Fiorindo)
Mark Appel Prospect Video (via Steve Fiorindo)