Nelson will have the final spot in the Diamondbacks' bullpen to begin the 2023 season, Nick Piecoro of the Arizona Republic reports.
Joe Mantiply is headed for a season-opening stint on the 15-day IL because of shoulder fatigue, and Nelson will essentially fill the vacancy. The 26-year-old left-hander registered a strong 2.19 ERA and 1.08 WHIP over 37 innings for the Diamondbacks in 2022.