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SCOTTSDALE, Ariz. -- Left-handed pitching prospects Joe Rock and Carson Palmquist hope to be part of the answer to the question that has hung over the Rockies through five straight sub-.500 seasons. Where is the quality and depth for their starting pitching?

Rock -- a second-round pick in the 2021 MLB Draft out of Ohio University -- and Palmquist -- a third-rounder in '22 out of the University of Miami -- are 23-year-olds who each spent time at Double-A Hartford last season. The Rockies extended a non-roster invitation to Spring Training to each of them in order to give them a chance to pitch and spend time in front of Bud Black and the Major League staff. Both hope to do well enough here and during the Minor League season to receive a call to the Majors.

Last year, the Rockies knew going in that they didn’t have depth to overcome injuries. Then Germán Márquez and Antonio Senzatela underwent season-ending Tommy John surgeries, and Ryan Feltner missed most of the year with a fractured skull. It was one of the many glaring defects that led to a 59-103 season. Depth pitchers gained experience, but the Rockies still lack the numbers of seasoned hurlers and up-and-comers that contending teams possess.

Rock and Palmquist will be prominent in MLB Pipeline’s soon-to-be announced Rockies 2024 Top 30 Prospects list, though. The farm system took a hit last season when elbow surgeries felled four of its top pitchers -- 2021 third-rounder McCade Brown, '23 top pick Gabriel Hughes, '23 second-round pick Jackson Cox and international gem Jordy Vargas. Even with those absences, this spring figures to be a preview of the system’s future.

“We’re getting to that point in our system where you’ll see more of our Minor League starting-pitching depth show up in Spring Training games -- Palmquist, Rock, Tanner Gordon [acquired from the Braves in a trade last year],” Black said. “We’ll see guys from Minor League camp -- Chase Dollander [last year’s top Draft pick] and Scott Sullivan [second-round pick last year], Connor Van Scoyoc [acquired in a trade with the Angels laser summer].”

Rock and Palmquist will be the first of the next starting prospects to have a chance on the Cactus League stage. Let’s get breakdowns from the pitchers themselves, then from Rockies director of pitching strategies Flint Wallace.

Rock on Rock

• Rock’s season at Hartford (1-10, 4.50 ERA) was affected by early-season left shoulder inflammation, but he pitched well when fully healthy, earning a promotion to Triple-A Albuquerque in September. Importantly, he developed a changeup to add to his solid fastball and swing-and-miss slider.

“I try to attack with my fastball and get to my slider,” Rock said. “I had to learn how to use my changeup. In college, I never really had to throw it. I have to learn to throw three pitches, and when the right time is to use them.”

• Rock reacted to his innings reduction -- from 115 2/3 innings at High-A Spokane and Hartford in 2022 to 92 2/3 innings in '23 by becoming a workout fiend, avoiding the drive thru and adding proper beef to a frame listed at 6-foot-6.

“Starting in August, I started offseason workouts and it carried over into this year,” Rock said. “I put on 20 pounds of good weight and I’m definitely in a good spot.”

Wallace on Rock

• The next step is consistency on all his pitches.

“We want him to be able to work his fastball on both sides of the plate,” Wallace said. “He can really bore it in on righties from his angle -- they have a hard time getting the barrel to it. He throws his changeup nicely. The slider is the pitch we need to focus on to get a little more consistent break.”

Palmquist on Palmquist

• On his pitch mix, which forces ground balls but also can miss bats at the top of the zone:

“The cutter that I started throwing this past season was a big jump for me, facing lefties and righties,” Palmquist said. “Double-A showed me how well it works against lefties -- ahead in the count, behind, whatever. I have a four-seam that has run and sink on it depending which release point it comes out in. It’s fun to see what it does. Then a circle-change, slider and fastball.

“Just don’t let me settle in, because once I start throwing strikes, it’s gonna be a long game.”

• On going from Rookie ball in 2022 to a dominant performance at Spokane (106 strikeouts in 70 innings over 15 starts) and a four-start stint at Hartford (28 strikeouts in 22 1/3 innings):

“I was just showing up week in and week out, getting outs, throwing strikes and giving the team a chance to win every time I was out there,” Palmquist said. “I kept grinding it out.”

Wallace on Palmquist

• He’s unique and effective:

“He’s one of those weird low-arm-slot guys who can pitch at the top of the zone because he has a good approach angle up there,” Wallace said. “That’s what deception is. His pitches don’t do what the arm slot would tell you. His ball behaves a little differently.

“Now, he can throw it down when he needs to get a ground ball. But when he can ride to the top of the zone, he does that really well.”