Diamondbacks Designate Kyle Nelson For Assignment

The Diamondbacks announced that left-hander Kyle Nelson has been designated for assignment. That’s the corresponding 40-man move for the signing of righty Jake Woodford, a move that was previously reported.

Nelson, now 28, has been with the Diamondbacks for years. He was claimed off waivers from the Guardians in the 2021-22 offseason. He showed some potential at times but required surgery to treat thoracic outlet syndrome in April of 2024 and his numbers since that procedure have been rough.

He missed the remainder of the 2024 campaign after going under the knife. Here in 2025, he has been on optional assignment, having tossed 17 Triple-A innings. He has allowed 16 earned runs in that time, leading to an 8.47 ERA. That’s a small sample of work but he also only has 12 strikeouts, a rate of 14.6% of batters faced. He has averaged just 89.9 miles per hour on his fastball.

There’s a big gap between that performance and what he was able to do a few years ago. In 2023, he logged 56 major league innings for the Snakes with a 4.18 ERA. He struck out 28% of batters faced while averaging 92 mph on his fastball.

Overcoming a thoracic outlet syndrome diagnosis is notoriously difficult. Pitchers like Matt Harvey and Chris Archer declined significantly later in their careers while Stephen Strasburg essentially had his career ended by the condition. On the other hand, Diamondbacks like Merrill Kelly and Ryan Thompson have each managed to engineer solid post-TOS seasons.

Nelson will now head into DFA limbo, which can last as long as a week. The waiver process takes 48 hours, so the Snakes could take five days to explore trade talks. Based on his injury absence and recent results, there may not be much interest.

If Nelson clears outright waivers, he will have the right to elect free agency but will probably decide to stay. Players with at least three years of big league service time have the right to reject an outright assignment, but those with less than five years have to forfeit their remaining salary in order to exercise that right. Nelson is in that three- to five-year window. He and the club avoided arbitration in the offseason by agreeing to a salary of $825K this year, a bit north of the $760K major league minimum.

Photo courtesy of Stan Szeto, Imagn Images