The Diamondbacks selected Nelson's contract from Triple-A Reno ahead of his scheduled start Monday in San Diego.

EDGE Analysis

Nelson will be making his MLB debut Monday, with his performance against the Friars likely to dictate whether he sticks around with the Diamondbacks as a member of the six-man rotation. The 24-year-old owns an unremarkable 5.43 ERA over 136 innings on the season, but he's shown significant improvement since making some mechanical tweaks in late May that enabled him to sharpen his command. Over his final three months at Triple-A, Nelson turned in a 4.61 ERA, 1.34 WHIP and 85:31 K:BB across 95.2 innings.

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.

Nelson will be called up from Triple-A Reno to start Monday's game against the Padres, Steve Gilbert of MLB.com reports.

EDGE Analysis

The team will afford its starters an extra day of rest this turn through the rotation and give Nelson a look at the major-league level. A second-round pick in 2019, Nelson flashed some impressive strikeout stuff at prior stops in the minors. His strikeouts are down this season, however, and his flyball tendencies have led to some home-run issues in the Pacific Coast League.

Nelson, who opened the year at Triple-A Reno, has allowed just two runs while striking out 13 in eight innings.

EDGE Analysis

One of Arizona's top pitching prospects, Nelson could make his big-league debut this summer. He has allowed eight hits and surrendered one home run while issuing just one walk through two starts.

Nelson allowed one run on three hits while striking out two and walking none over four innings in Friday's spring game against the Rockies.

EDGE Analysis

Nelson, the organization's Minor League Pitcher of the Year for 2021, has been throwing since minor league camp opened last month, so it's natural for him to be up to four innings at this stage of spring. Drafted as a reliever in the second round of the 2019 draft, Nelson is being groomed as a starter for now. He went a combined 7-4 with 3.17 ERA in 22 starts for High-A Hillsboro and Double-A Amarillo in 2021.