clock menu more-arrow no yes mobile

Filed under:

Colorado Rockies prospects: No. 11, Joe Rock

The lefty was one of the few pitching PuRPs to stay healthy in 2022

If you buy something from an SB Nation link, Vox Media may earn a commission. See our ethics statement.

11. Joe Rock (435 points, 24 ballots)

The 6’6”, 200-pound, 22-year-old lefty starter is an imposing figure on the mound. Rock was the 68th overall pick of the 2021 draft and signed for a slot bonus of $953,100. The earned that draft placement with a breakout 2020 summer performance in the All American Collegiate League, followed by a strong 2021 at Ohio University. After the draft, he had a decent cameo in the ACL (one earned run on five hits with 11 strikeouts), but that was only eight innings.

Rock, who was one of the few PuRP pitching prospects with a clean bill of health in 2022, was assigned to High-A Spokane to begin the season, where he was 2.2 years younger than league average. In 107 23 frames across 20 starts, Rock had a 4.43 ERA (4.42 xFIP) with a 1.23 WHIP, 9.1 K/9 rate, and 3.8 BB/9 rate. That includes a seven-inning, one-hit, nine-strikeout gem in early June which was followed by an outing where he struck out ten in just five innings. Rock had two rough starts to end August, but before that was keeping his ERA solidly under four as a young player in the league. Rock was better against lefties (.653 OPS against) but was still effective against right-handed batters (.703 OPS).

In September, the Rockies promoted Rock to Double-A Hartford, where he was 3.5 years younger than league average. With Hartford, he made two starts and got knocked around a bit: nine runs on nine hits and five walks with 11 strikeouts in eight innings (but a 3.90 xFIP indicated Rock was a bit unfortunate to get those results).

Here’s some video of Rock from late 2021 courtesy of FanGraphs:

Baseball Prospectus listed Rock 20th in the system in their November write-up:

A long, lean, fastball/slider lefty with a bit of deception, Rock leans heavily on his mid-80s breaking ball, which shows sharp two-plane break and has above-average projection. His fastball sits low-90s, but there might be more in the tank either in short bursts or given more physical development. The fastball is merely around to set up the slider, as Rock doesn’t have much command of or carry on the pitch. He will probably stay stretched out for another season as a starter in Hartford, but his eventual home will be working the middle innings out of the bullpen.

Keith Law of the Athletic ranked Rock 17th in the system last week:

Rock shows three pitches with a low-90s fastball, average slider, and above-average changeup, but works with 40 command and doesn’t show great feel for using his stuff. He was a disaster from the stretch last year as well. He has the stuff to start but the lack of command and feel probably points to relief.

Rock was listed as a 40 FV prospect (outside the top 14) by’s Kiley McDaniel last week:

Rock is a 6-6 lefty who popped up at mid-major Ohio in the 2021 draft spring and eventually went 68th overall. He has a solid-average three-pitch mix and fringy command, though some scouts worry his arm action portends command and injury issues down the road.

In the profile accompanying the above video, FanGraphs ranks Rock 20th in the system as a 40 FV prospect:

Rock has an ideal pitcher’s build and an incredibly loose and fluid delivery for a guy his size. Coming off a redshirt 2020 at Ohio (he didn’t pitch at all before the shutdown), Rock had a huge uptick in performance — 117 K, 88.2 IP, 27 BB — and became famous after an early-season no-hitter. His frame, small school/cold weather pedigree and the missed year of reps are all late-bloomer traits that indicate his already solid stuff could become better with pro development. Rock’s fastball touches 96 mph, sits 91-94, and has tailing action that’s aided by his natural deception. It takes hitters a few looks at Rock from the batter’s box to really seem comfortable in there, especially the lefties. Flashes of an above-average slider and changeup occurred during instructs, though Rock’s finishing pitch has been his slider to this point. It’s imperative for Rock’s changeup to develop as it will help keep righty hitters off his fastball, which they get a nice long look at due to his arm slot. He has a leg up in this regard because of his mechanical fluidity and tailing fastball shape, which mimics that of his change. Even with a fully developed changeup, Rock’s fastball may end up playing best in shorter bursts rather than two and three times through a lineup, but at this moment he has a shot to pitch toward the back of a rotation.

Rock was ranked #85 among 2021 draft prospects by and is currently 17th in the system ranking as a 45 FV prospect:

Already sitting in the low 90s consistently, there could be more velocity to come as Rock adds strength to his 6-foot-6 frame. He was up to 97 mph in his brief looks last summer and it plays up even more because he gets huge extension, so the ball gets on hitters in a hurry. His breaking ball is trending upwards as well, a pitch that’s somewhere between a power curve and a slider.

The Rockies knew coming in that Rock would have to work on his changeup since he didn’t need it much in college, but he has good feel for it and it could be a very effective third pitch once he trusts it. His lower slot provides funk and deception, making him very difficult to square up. He’s aggressive and loves going right after hitters, with the chance to do so in a big league rotation in the future.

Rock has an intriguing profile, boasting a projectable starter’s frame with a deceptive delivery. He’s shown improved velocity and feel for his change since signing, so his prospect arrow is up despite getting knocked around in his last few starts. That written, I’m a bit behind where the electorate is on Rock as a pitching prospect, ranking him 14th on my ballot as a 40+ FV prospect with the pedigree and stuff weighed against the reliever risk (which is highlighted especially in some of the more recent scouting reports).

To move higher, Rock’s command and another secondary pitch will need to emerge to get high minors and MLB hitters out. The 2022 season was encouraging; let’s hope Rock can do it (preferably as a starter) in a return to Double-A next year against more advanced hitters.