The Diamondbacks announced this afternoon that they’ve placed right-hander Ryne Nelson on the 15-day IL due to shoulder inflammation, retroactive to September 11. Left-hander Brandon Hughes was selected to the roster from Triple-A Reno to replace Nelson, and catcher Andrew Knizner was designated for assignment to make room for Hughes on the 40-man roster.
Nelson, 26, entered the season seemingly squeezed out of the club’s rotation mix by the club’s signings of lefties Eduardo Rodriguez and Jordan Montgomery over the offseason. That was hardly surprising after a pedestrian 2023 season where he pitched to a below-average 5.31 ERA and 5.07 FIP across 29 appearances (27 starts) for Arizona last year. That said, injuries throughout the club’s rotation have kept Nelson in the club’s rotation almost all year. He’s made the most of the unexpected opportunity and pitched quite well, with a 4.33 ERA that’s roughly league average (96 ERA+) and a strong 3.77 FIP in 147 2/3 innings of work. While that hasn’t necessarily been enough to give him a leg up over fellow youngster Brandon Pfaadt (4.42 ERA, 3.54 FIP) at the back-of-the-rotation, injuries and ineffectiveness have hampered both Rodriguez and especially Montgomery this year, leading the Diamondbacks to kick the latter to the bullpen late last month.
With Nelson now headed to the IL, Montgomery appears ticketed for a return to the rotation as noted by Alex Weiner of AZ Sports. It’s been a disastrous year for the 31-year-old lefty as he pitched to a 6.44 ERA and 4.57 FIP in 19 starts before getting kicked from the rotation, though he’s looked a bit better with a slightly more palatable 4.85 ERA and 4.40 FIP since moving to a multi-inning relief role. For the time being, the Diamondbacks will have to hope that the brief sojourn to the bullpen has helped Montgomery figure things out enough to pitch effectively as a starter for the time being. Fortunately, manager Torey Lovullo told reporters (including Nick Piecoro of The Arizona Republic) that the club is optimistic regarding Nelson’s injury and hopes he’ll be able to return after a minimum stay on the shelf, which could allow him to make one more start before the regular season comes to an end.
Montgomery’s impending move back into the rotation leaves the club down a lefty in the bullpen, and that’s a call that Hughes now figures to answer. Drafted as an outfielder by the Cubs in the 16th round of the 2017 draft, Hughes converted to pitching back in 2019 and worked his way through Chicago’s minor league system to make it to Wrigley Field in 2022. The southpaw impressed with a 3.12 ERA and 4.64 FIP with a 28.5% strikeout rate in 57 2/3 innings of work for the rebuilding Cubs and even picked up eight saves after taking over the closer role in Chicago following the departures of David Robertson and Chris Martin at that year’s trade deadline.
Unfortunately, Hughes was hampered by knee surgery that cost him the majority of the 2023 season and found himself non-tendered by the Cubs last fall. That led him to sign with the Snakes on a minor league deal, but he’s struggled badly in limited opportunities in the majors with the club this year as he’s posted a 10.29 ERA and 9.96 FIP in 14 innings of work. That being said, his numbers with Triple-A Reno this year have been nothing short of excellent as he’s posted a 2.03 ERA and struck out 24.9% of opponents in 48 2/3 innings of work. Now he’ll get another opportunity in the Arizona bullpen alongside fellow lefties Joe Mantiply and A.J. Puk.
Hughes will take the 40-man roster spot of Knizner, who the Diamondbacks claimed off waivers from the Rangers just over a month ago. The 29-year-old backstop didn’t make it to the big leagues with Arizona, instead slashing a decent .274/.357/.397 in 20 games with the club’s affiliate in Reno, but appeared in 35 games in the majors with Texas earlier this year after spending half a decade as an up-and-down catcher for the Cardinals. His time with the Rangers did not go particularly well, as he hit just .167/.183/.211 in 93 trips to the plate. That paltry offensive production was particularly disappointing following the best offensive season of Knizner’s career last year, when he pitched to a .241/.288/.424 slash line with ten homers in just 241 trips to the plate. Should Knizner go unclaimed on waivers, the club would have the opportunity to outright him to the minor leagues but he’d be poised to head into minor league free agency this November.