Nelson, who will make his MLB debut for Arizona on Monday, implemented two mechanical adjustments late in May that improved his results going forward, Theo Mackie of The Arizona Republic reports.

EDGE Analysis

Nelson was sitting on a 7.36 ERA through nine starts for Triple-A Reno in the Pacific Coast League, notoriously known as a hitters league. That's when the Diamondbacks spotted his arm path was long, meaning he was reaching too far back on each pitch. The right-hander was given exercises designed to shorten the path, and the results were immediate. "The carry came back," pitching coordinator Dan Carlson said. "The command came back. And also the breaking ball got much, much sharper and then with the slider and change, he was able to keep those things in the strike zone." Around that same time, Nelson ditched an adjustment to his lower mechanics, a shorter leg kick he implemented during the offseason. In 17 starts since, Nelson pitched to a 4.61 ERA, lower than the league average 5.43 ERA for the PCL.