Reno, Nevada —— Entering play on Wednesday night, Arizona Diamondbacks right-handed pitching prospect Frank Duncan is 6-5 with a 6.08 ERA over 16 starts for the Triple-A Reno Aces, with 118 hits allowed over 90.1 innings pitched in 2017 and 54 strikeouts against 27 walks. On June 20, I observed a home start for the former Pittsburgh Pirates prospect who was acquired over the winter by the Arizona Diamondbacks in the Phil Gosselin trade. Below is Baseball Census‘ full Frank Duncan scouting report, including video.
Frank Duncan Scouting Report — Video
Our full video of Arizona Diamondbacks right-handed pitching prospect Frank Duncan comes from that June 20 start at home against the Las Vegas 51s:
In that start you watched above, Duncan went three-plus innings, and allowed seven earned runs on ten hits and three walks while striking out just two batters. For more baseball prospect videos, please click here and subscribe to our YouTube channel.
Frank Duncan Scouting Report — Notes
Frank Duncan works 86-89 mph with his fastball, topping out at 90 mph. It’s a two-seam offering with modest arm-side run and occasionally some sink when down in the zone. He couples it with a 79-83 mph changeup that tumbles, and his good arm action can create some swings and misses when it’s on. He also throws a 76-80 mph slider (max 81 mph) that he went to early and often on June 20 in a futile effort to keep Las Vegas hitters off balance. He threw one or two decent sliders that missed bats—twice he got New York Mets prospect Phillip Evans out on his front foot, and that’s saying something with Evans’ contact skills—but too many of his sliders backed up or spun like a cement mixer with extremely little break or depth.
Duncan throws from a three-quarters arm slot, slinging the ball in a way reminiscent to me of Colorado Rockies prospect Ryan Castellani, but without the plus velocity. You think that’d be effective for pitch life, but in this June 20 start Duncan’s stuff was incredibly flat and struggled to move off one plane. Hitters had no trouble timing it and squaring him up, and the combination of one plane with no velocity to keep hitters honest left Duncan in a bad spot. Couple that with his cement mixer slider that broke very little and backed up too often, and ten hits allowed over three innings is about right.
Frank Duncan Scouting Report — Projection
It’s always difficult to project a pitcher based on one start alone (was it his worst one of the year?) but Frank Duncan’s June 20 work is comparable to some of the outcomes from the rest of this season, and it tells a story: he’s far too hittable with inconsistent command of three pitches that don’t have enough bite to keep him above water against a good lineup. Yes, the Pacific Coast League is a hitter’s league, and Duncan is coming off a very good 2016 that included 20 strong starts at Pittsburgh’s Triple-A affiliate before the trade, but the new Arizona Diamondbacks prospect is struggling right now with little margin of error thanks to below-average velocity and flat pitch life. Surprisingly, he’s a top-30 guy per MLB Pipeline, though that likely says more about the Diamondbacks’ relatively barren farm system than anything else.
Long term, the righty is likely ticketed for long relief. Despite imprecise command his control is pretty good, and he’s comfortable using all three pitches with regularity even though they grade out as average or below. He’s too hittable with too little velocity and pitch life to find himself in a sustained rotation role, even on the back end, and so any big league role ought to be as a long reliever throwing low-leverage innings. But still just 25 years old and only in his fourth professional season, Frank Duncan has some time to left to develop in Triple-A and see if he can’t make some kind of impact on the Arizona Diamondbacks.