DENVER -- Aspects of the Minor League statistical performances of outfielder Sam Hilliard and left-handed starting pitcher Ryan Rolison justify their selections as the Rockies’ MLB Pipeline Prospects of the Year. But, deeper than the numbers, their willingness and success at improving when challenged confirm the choices.

Each team's Hitting and Pitching Prospects of the Year were chosen by the MLB Pipeline staff. To receive consideration, players must have spent at least half the year in the Minors and appeared on the team's Top 30 Prospects list.

The left-handed-hitting Hilliard, 25, who made a splash with two home runs in his first four Major League games, had a standout year at Albuquerque -- .262 with a .335 on-base percentage, 35 home runs and 101 RBIs in 126 games.

Rolison, 22, needed just three starts (0.61 ERA, 14 strikeouts in 14 2/3 innings) at Class A Asheville to pitch his way to Class A Advanced Lancaster. In the hitter-friendly California League, he went 6-7 with a 4.87 ERA, with 118 strikeouts to 38 walks in 116 1/3 innings.

Rockies senior player development director Zach Wilson described how each player met challenges:

On Hilliard:

Hilliard struck out 151 times in 121 games last year at Double-A Hartford. The 164 strikeouts in Triple-A and 15 in 45 Major League plate appearances show that there’s work to do, but it’s being done.

“It really started about the last month of last year,” Wilson said. “We changed his swing last year, with his involvement, where we went from sort of a toe-tap to more of a leg kick that we see now. That’s allowed him to stay back on breaking balls, allowed him to recognize pitches a little longer.”

What are the possibilities for Hilliard?

“He’s got a chance to do major damage at any time,” Wilson said. “We call him a mistake power hitter. Even when he doesn’t barrel it up perfectly or get the perfect swing off, the ball’s got a chance to go out.”

A former pitcher/position player in college, Hilliard -- with impressive size (6'5") and speed -- has made strides with the glove.

“He played a lot in center field in Triple-A, and that helped him be better on the corners and he’s played very good defense since he’s been up,” Wilson said. “So a lot of good development for Hilliard this year.”

On Rolison:

The move to Lancaster allowed Rolison to experience the cycle of success (1.22 ERA through his first eight starts), struggle (7.27 through the next 12) and rebound (3.12 in his final five).

“He found success early there, the hitters in that league started to make an adjustment to him,” Wilson said. “He also started to get fatigued, being that is his first full season. So those things came out a little bit. But what’s great about Ryan is he also understood what he had to do to adjust.”

Even with the fatigue, Rolison pitched 131 combined innings -- right to his pre-set limit -- in his first full pro season. So he was pushed without overdoing.

“We did skip him a start in there to give him a little bit more of a rest. That was important to what was going on with him.” Wilson said. “His breaking ball, more due to fatigue than anything else, started getting a little slurvy. So we really had to get his curveball -- which is a big strength of his -- tightened back up, which it did quickly because he’s got such a great feel to pitch.”

Rolison gave up 22 home runs at Lancaster, but he showed he wasn't afraid to challenge hitters.

“One of his major strengths is he’s not afraid to continue to throw strikes,” Wilson said. “Even when he’s getting hit around a little bit because maybe he’s not commanding it the way he wants, he’s not going to walk people, either.

“He worked diligently on his changeup this year. That was the focus of his and ours going into the season. There’s no question he took another step with the changeup, and he’s very proud of the changeup. So that is a part of who he is. He attacks. He doesn’t walk guys. He’s going to make guys get on base through making contact.”