Holmberg is one of six hurlers on Arizona's list of top 10 prospects, a group that also includes last year's top Draft picks, Trevor Bauer and Archie Bradley, and two other arms who've passed through Visalia in the last few seasons: Pat Corbin and Tyler Skaggs.
A second-round selection by the White Sox in the 2009 Draft, Holmberg was part of a deadline swap between Chicago and Arizona in July 2010 and suddenly found himself as another talented arm among many, both behind and ahead of him.
Holmberg, who has won his last five starts dating back to April 27, has approached these high standards of excellence head-on. He views the competition as a healthy way to stay on top of his game, as well as a way to push his teammates harder.
He learned similar basic lessons from his days with Chicago and Arizona. Holmberg says the key to his success has been his work on fundamentals of pitching, like keeping the ball down and strong command of all his pitches.
Holmberg throws a fastball, curve, slider and change-up and feels comfortable with all four weapons. Each one has required development, something he started in Chicago and continued after the trade.
"I learned a lot in extended spring training with the White Sox about throwing inside and using the breaking ball," he said. "The Diamondbacks instructors really expanded on that."
Holmberg shouldered a heavy workload last season, which was both his first shot at full-season ball and his first season with the D-backs. He pitched 154 1/3 innings between Class A South Bend and Class A Advanced Visalia. He recorded 157 strikeouts and 48 walks last year, a testament to his control.
"It's a learning experience," he said. "I'm here to expand on my repertoire and command."
Holmberg faced two options after his senior year of high school: pitch for the University of Florida or sign with the White Sox. He opted for the pro route and is satisfied with his choice.
"I wanted to get my career started," he said. "It was a tough decision, but I think I chose the right one."
Turning the tables: Lake Elsinore right-hander Donn Roach has been dominant since he was traded from the Los Angeles Angels of Anaheim to the San Diego Padres earlier this month. The Las Vegas native has allowed one earned run over three starts with his new organization, fanning 18 in 17 innings. Overall he is 7-0 with a 1.69 ERA and has 47 strikeouts in 58 2/3 frames. Last week he enjoyed a particularly strong performance against Bakersfield, allowing two hits and two unearned runs over seven innings.
Count on Clark: Modesto first baseman Jared Clark unleashed the power in two games last week, hitting four homers and driving in eight runs. The 26-year-old first baseman moved into a tie for the team lead with nine long balls and 38 RBIs. He is in his second year at the Class A Advanced level and already has more homers and RBIs than he did all of last season.
Pearl hurls gems: Bakersfield closer Brian Pearl, who ranks near the top of the league with 15 games finished and seven saves, has been particularly stingy of late. The University of Washington product has allowed one run on four hits over 10 2/3 innings in May. Overall he has 25 strikeouts and three walks in 22 1/3 frames. He's been especially tough on the road, yielding one run with 14 strikeouts in nine contests while nailing down four saves.