{"id":508351,"date":"2026-01-06T19:27:12","date_gmt":"2026-01-06T19:27:12","guid":{"rendered":"https:\/\/www.rawchili.com\/mlb\/508351\/"},"modified":"2026-01-06T19:27:12","modified_gmt":"2026-01-06T19:27:12","slug":"2025-diamondbacks-player-reviews-4-ryne-nelson","status":"publish","type":"post","link":"https:\/\/www.rawchili.com\/mlb\/508351\/","title":{"rendered":"2025 Diamondbacks Player Reviews: #4 Ryne Nelson"},"content":{"rendered":"

Rating: 8.482025 Stats: 154 IP, 3.39 ERA, 3.5 bWAR, 2.0 fWARDate of Birth: February 1st, 19982025 Earnings: $806,400 ($389,113 Pre-Arbitration Bonus)2026 Status: 1st-Year Arb Eligible, 2029 Free Agent\"\"<\/a><\/p>\n

After going unselected in the 2016 MLB Draft, Ryne Nelson attended the University of Oregon. There he\u2019d spend his first two years splitting time between the infield and the bullpen, before deciding to focus solely on pitching. That was a wise decision for Ryne, as he\u2019d raise his prospect status enough that the Arizona Diamondbacks drafted Ryne Nelson in the second round of the 2019 MLB draft with the 56th overall pick. Coincedentally, Nelson would head back to the state Oregon for his pro debut the same year, tossing 18 2\/3 innings with a 2.89 ERA, 3.33 FIP, and 3.26 xFIP for the (at the time) Low A short season affiliate of the Diamondbacks, the Hillsboro Hops. Like every other player in affiliated baseball, the Covid-19 pandemic cost Nelson all of his 2020 season, and part of his 2011 season. When MILB finally started up again, Ryne Nelson would find himself back in Oregon, playing for the now High A level Hillsboro Hops, which essentially swapped levels with the Visalia Rawhide, due to minor league baseball undergoing a massive realignment. Nelson would toss 39 \u2153 innings, putting up a 2.52 ERA. with a 3.27 FIP (Fielding Independent Pitching) and 3.99 xFIP (adjusted FIP) That would be good enough for Nelson to earn another promotion, this time to the much less pitcher friendly, high offensive scoring environment of AA Amarillo Sod Poodles in the Texas League.<\/p>\n

In Amarillo, Nelson pitched another 77 innings with a 3.51 ERA, 4.06 FIP, and 3.50 xFIP to finish out the 2021 season. The next season the D\u2019Backs promoted Nelson to the AAA level Reno Aces, who play in the even more hitter friendly environment of the Pacific Coast League. Considering just how hitter friendly the ballparks in the PCL are, the fact that Nelson put up an ERA of 5.43, 5.49 FIP, and 5.51 xFIP in the 136 innings he pitched isn\u2019t that surprising, especially for anyone whose paid attention to the D\u2019Backs farm system for any length of time.<\/p>\n

Regardless of the results, the D\u2019Backs called up Nelson in September when the rosters expanded. He\u2019d shine in his MLB debut against the Padres on September 5th, tossing an absolute gem of a performance; Seven innings pitched, no walks or runs, four hits, and seven strikeouts. In his next start against the Dodgers, Nelson would toss six more scoreless innings, giving up just a pair of hits and a pair of walks, while striking out six. His third and final start of the 2022 season didn\u2019t go nearly as well with Nelson only going 5 \u2153 while allowing four runs (three earned) on three hits, two of which were HRs. That\u2019d leave him with a 1.47 ERA, 2.23 xERA, but also a 3.77 FIP, and 4.69 xFIP, with the latter two stats being an omen for the following season, which wouldn\u2019t go nearly as well.<\/p>\n

In 2023, Nelson pitched 144 innings with a 5.31 ERA, 5.25 FIP, and 5.07 xFIP in the regular season, and a 5.68 ERA in the 6 \u2153 IP out of the bullpen in the postseason.<\/p>\n

2024 would see Nelson improved significantly. In the 150 \u2154 innings, he lowered his ERA over a full run down 4.24 ERA and improved his fWAR total by 1.5. The advanced statistics give an even clearer picture of his improvement: 4.14 xERA, 3.74 FIP, 3.98 xFIP. However, looking at his 102 ERA-, his season was actually 2% worse than league average, though it was an improvement on the 129 and 120 ERA- he put up the previous two seasons.<\/p>\n

At the end of spring training, the plan was for Nelson to be moved into the bullpen and that\u2019s how he\u2019d start his season, pitching in relief. Things didn\u2019t exactly go to plan as half the pitching staff ended up on the injured list, with Nelson being moved back into the rotation as a result of big FA signee Corbin Burnes hitting the IL and needing Tommy John surgery. Now in the starting rotation, Nelson thrived and fully establish himself as a starting pitching, and was arguably better than he was as reliever.<\/p>\n

In the 26 innings he pitched as reliever in 2025, Ryne Nelson had a 4.50 ERA, but in his 126 innings as a starting pitcher, he had 3.16 ERA. It is worth noting though that the underlying metrics are all much better for Nelson as a reliever, than they are as a starter. For example his .269 wOBA as a reliever vs his .289 wOBA as a starter. Altogether Nelson pitched 154 innings with a 3.39 ERA, 3.89 xERA, 3.73 FIP, and a 4.05 xFIP, with his 80 ERA- showing he was 20% better than league average. There are some signs of trouble going forward, most notably the negative pitch value for his curveball, which became less valuable than the year before (-1.8 wCU vs +2.5 in \u201824). This is in addition to the negative value of his change up (-2.5 wCHU), which while still better than \u201824 (-5.6), was still not very good. Some of the negative value of his curve is a result of Nelson\u2019s curve being thrown harder and more often, which probably affects the ability for the model to identify it correctly in the first place, but throwing it more often gives batters a chance to make better contact, more often. As far as his change up goes, Nelson basically scrapped it completely, but when he did throw it, it was a much harder pitch. Previously he had 12 MPH of separation between his fastball and change up, which is borderline elite, but with only 8MPH of separation it\u2019s a mediocre pitch.<\/p>\n

If Nelson can\u2019t rely on his offspeed\/breaking pitches, batters will eventually adjust their approach, making his other good pitches much less effective.<\/p>\n

Merill Kelly coming back takes a lot of pressure off Nelson to perform. Considering the underpeformance of Brandon Pfaadt, Eduardo Rodriguez, AND so called staff \u2018Ace\u2019 Zac Gallen (now a FA), on top of the injury and subsequent surgery to the staff\u2019s planned ace Corbin Burnes, it put Ryne Nelson in the awkward position of being the best returning starting pitcher in 2026 that\u2019s currently on the D\u2019Backs roster. It\u2019s mostly a matter of refining his offspeed pitches and improving upon further the things that were working in 2025. If he can improve his curveball and changeup enough that they are effective pitches again, I think Nelson could end up being one on the best starters in the league. Without improving those pitches, I can\u2019t see Nelson developing into a top of the rotation pitcher, but as of right now, I think he\u2019s well on his way to being a #2\/#3 starter.<\/p>\n","protected":false},"excerpt":{"rendered":"Rating: 8.482025 Stats: 154 IP, 3.39 ERA, 3.5 bWAR, 2.0 fWARDate of Birth: February 1st, 19982025 Earnings: $806,400…\n","protected":false},"author":2,"featured_media":508352,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[2404],"tags":[146,22,38434,4314,5,38,4],"class_list":{"0":"post-508351","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-arizona-diamondbacks","8":"tag-arizona","9":"tag-arizona-diamondbacks","10":"tag-arizona-diamondbacks-analysis-commentary","11":"tag-arizonadiamondbacks","12":"tag-baseball","13":"tag-diamondbacks","14":"tag-mlb"},"share_on_mastodon":{"url":"https:\/\/channels.im\/@mlb\/115849805939342005","error":""},"_links":{"self":[{"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/posts\/508351","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/comments?post=508351"}],"version-history":[{"count":0,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/posts\/508351\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/media\/508352"}],"wp:attachment":[{"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/media?parent=508351"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/categories?post=508351"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.rawchili.com\/mlb\/wp-json\/wp\/v2\/tags?post=508351"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}