The D-backs had an unfortunate run of bad luck in 2021 when it came to the health of their two top prospects per MLB Pipeline rankings without outfielder Corbin Carroll injuring his right shoulder while hitting a home run in the first week of the Minor League season and shortstop Jordan Lawlar injuring his left shoulder while diving for a ball.

That shouldn't obscure the overall positive year in player development that the D-backs had, particularly on the pitching side of things.

• D-backs' Top 30 prospects

"We probably had the best development pitching year in the Minor Leagues since I've been here," D-backs GM Mike Hazen said. "We have a large group of pitchers that fit that profile, most of whom we see as future starting pitchers."

Here's a look at some of this year's Minor League happenings:

3 players who forced their way onto the radar this year

1. Alek Thomas: OK, so Thomas was always on the radar, but whatever timetable you may have had for him, it seems safe to say he's sped it up. The outfielder started the year at Double-A Amarillo where he put up very good numbers hitting .283/.374/.507 over 72 games. Promoted to Triple-A Reno on Aug. 16, the 21-year-old absolutely raked with a .369/.434/.658 slash line in 34 games.

While it's safe to say that Reno inflates some offensive numbers, it was still an impressive stretch as Thomas homered eight times in 166 plate appearances.

2. Ryne Nelson: The right-hander is part of a wave of D-backs pitchers currently making their way through the system. Selected in the second round of the 2019 Draft out of Oregon, Nelson was named the organization's Pitcher of the Year after splitting time between High-A Hillsboro and Double-A Amarillo.

While some may have pegged him as a short reliever coming out of college, Nelson has improved his mechanics, which in turn has led to better command and consistency. Both were on display this past season and his dominance -- he was fourth in all of Minor League Baseball in strikeouts -- has the team excited about his future.

3. Brandon Pfaadt: Selected in the fifth round of the 2020 Draft, Pfaadt had a whiplash-inducing rise through the Arizona system in 2021. The right-hander opened the year with Low-A Visalia and after seven starts was promoted to Hillsboro where he had a 2.48 ERA over nine starts, including 67 strikeouts and 39 hits allowed in 58 innings.

Looking to challenge him even more, the D-backs sent him to Amarillo where he made six starts to finish out the year. The 23-year-old has shown an ability to maintain his stuff later into his starts and is a name that D-backs fans will be hearing a lot more in the next year.

2 possible breakout players

1. Cooper Hummel

Hummel was acquired by the D-backs from the Brewers as part of the return for Eduardo Escobar at the Trade Deadline. While he is not currently among Arizona's Top 30 prospects per MLB Pipeline, the 26-year-old presents some interesting possibilities for the D-backs.

Hazen liked Hummel's versatility -- he has played first, third, left and right field in addition to catching -- and he's a switch-hitter who has a good feel for the strike zone. Those two attributes could make him an intriguing role player in 2022.

2. Seth Beer

Beer, who came over from the Astros at the 2019 Trade Deadline as part of the package for Zack Greinke, finally got his big league chance in September. In his first at-bat he hit a pinch-hit home run, and he started at designated hitter the next two games against the Mariners in Seattle and went 3-for-7. Unfortunately for Beer, he dislocated his left shoulder in the first inning of his first start at first base while diving for a ball and he required season-ending surgery.

If there is a universal DH next year, Beer would be an intriguing candidate for the D-backs to use there.

One big question: What will happen with Kristian Robinson?

Robinson was ranked in the top five of the D-backs' prospects as recently as earlier this year, but a legal issue off the field has stalled his development and put his future status up in the air. It remains to be seen whether the 20-year-old outfielder will be able to get a visa to return to the United States from the Bahamas.