DENVER -- Left-handed starter Ryan Rolison, the Rockies' No. 2 prospect according to MLB Pipeline and the organization’s highest-rated pitcher, has been promoted from Double-A Hartford to Triple-A Albuquerque, Rockies assistant general manager of player development Zach Wilson said Monday.

Rolison, 23, was a first-round MLB Draft pick in 2018 out of Ole Miss. He was 2-1 with a 3.07 ERA in three starts at Hartford.

The promotion was based on a couple key areas the Rockies targeted: zeroing in on the changeup to make it a key part of his strategy, and tightening his direction toward the plate. Rolison has been working on those changes over the better part of the last three months -- at Spring Training and during the alternate training site in Scottsdale, Ariz., and during the early portion of the Minors regular season.

One advantage to sending him to Double-A was Hartford pitching coach Frank Gonzales, a fellow left-hander and father of Mariners left-hander Marco Gonzales. Rolison worked with the elder Gonzales at Class A Lancaster in 2019, and at last year’s alternate site in Denver.

Another advantage was psychological.

“Not that it was going to happen with Ryan, but then again it happens to everybody -- you have the potential to take your eye off the ball of development things that are important, because now you're at Triple-A and thinking, ‘I'm just a phone call away,’ Wilson said. “There's a tendency at times to get away from things that you should be focused on. So we sent him to Double-A, where he [could] really truly just be focused on getting better, as opposed to trying to perform to get to the big leagues.

“He was worried only about things he needed to do to be a better pitcher. Because of that focus, he was able to knock them out quickly.”

Rolison’s key attribute is the ability to spot his fastball, and he is solid with breaking balls. The Rockies believed he needed true understanding of the changeup.

“Our focus was making sure that that changeup was at a place where he became fearless -- to use it in all sorts of different ways, different counts to get contact, to get swing-and-misses,” Wilson said. “To get focused on it -- not just to mix it in, but to get outs with it.

“He showed that, not just over three starts in Hartford, but while he was at the alternate site as well.”

The Rockies are confident challenging Rolison to hold onto the improvements with the changeup and the delivery, which should make his fastball and breaking pitches more crisp, while competing for a callup to the Majors.

“The closer you get to the big leagues, it gets to the point where you're just trusting what you've done in your process, and you are pitching to get outs and to win ballgames,” Wilson said. “When you get to the big leagues, that’s all that matters.”