New Starting Pitchers: Three Relievers Turned Starting Pitchers

It’s hard to project how a reliever will turn into a starting pitcher, especially within a season. We expect velocity to decline as a starter, and we imagine arsenals will evolve as they pitch deeper into games. Today, we’ll dive into three pitchers who made this transition in 2026. Two of these pitchers were on fantasy rosters this year and in the past, both entering the season in different roles than they have now. The third’s path to fantasy relevance was through deeper formats.

Like most of my pitching articles, we’re looking at the underlying skills and metrics, diving into the arsenal, movement profiles, locations, and command.

Ben Brown, SP/RP, Cubs

We’ve been sucked into the Ben Brown roller coaster before, dreaming on his stuff. With injuries to Matthew Boyd, Cade Horton, and Justin Steele, the Cubs needed to move Brown into the starting rotation. It’s only been two starts, but Brown threw eight scoreless innings, with a 28.6% K-BB%, 0.38 WHIP, .067 BABIP, 100% strand rate, and a 15.3% swinging-strike rate. Since moving into the rotation, Brown has been relying heavily on his knuckle curve and four-seamer, with those two pitches accounting for nearly 80% of his arsenal. A sinker and changeup filled the rest of his pitch mix.

The sinker is a new pitch for Brown after primarily relying upon his four-seam and knuckle curve 95% of the time. Notably, Brown has been lowering his four-seam usage from 62.7% (2024) to 55.6% (2025) and 36.5% (2026). He mainly introduced his sinker toward right-handed hitters, throwing them 41.5% of the time to lead his mix in 2026, as seen in the visual below.

Brown’s sinker drops more three inches and generates nearly eight additional inches of arm-side fade than the four-seamer. We see Brown’s sinker filling the tiny void between the four-seam and changeup below.

That slight movement profile difference leads Brown’s sinker to elicit weak contact (.246 wOBA, .242 xwOBA), inducing a 63.6% groundball rate. Adding the sinker helps Brown’s arsenal against right-handed hitters because it should help keep hitters off-balance, when paired with a hard four-seamer and a slower knuckle curve. Theoretically, opposing hitters might be expecting the four-seamers, yet he throws a sinker that runs more toward the inside part of the plate for right-handed hitters, as seen in the heatmaps below.

Based on the fastball heatmaps against right-handed hitters, we see that the sinker has been thrown lower in the zone in 2026 compared to his four-seam usage in 2025. Brown’s sinker has been performing well against right-handed hitters, evidenced by the visual below showing slugging percentage per balls in play. Brown has been making an arsenal adjustment, translating into positive outcomes.

Besides Brown’s sinker, his changeup continued to evolve, adding nearly four inches of downward movement while maintaining its arm-side fade in 2026. Most notably, Brown’s changeup developed an above-average vertical movement profile, aligning with his career-best 104 Stuff+. Brown’s changeup gives him an additional offering to left-handed hitters. In the small 2026 sample, Brown’s changeup has been helpful for weak contact (.000 wOBA, .205 xwOBA) and groundballs (80%).

With Brown’s additional downward movement, he has been throwing changeups in the zone 30.3% of the time in 2026, significantly below his 42.5% career zone rate. That coincides with Brown’s changeup allowing a career-low contact rate, as he peppers it low and below the zone.

Interestingly, Brown’s changeups have been thrown lower and more toward his glove side, which might be concerning against left-handed hitters. Brown may want to throw the changeup lower in the zone, yet more toward the outside corner of the plate toward lefties. The changeup still looks like a work in progress, but we’re seeing positive changes in 2026.

We’ll have to be patient with Brown as he evolves as a starting pitcher. The results have been positive, though it will probably be bumpy as he increases his workload. Brown typically boasted above-average stuff, and he thankfully added depth to his arsenal in a helpful way. Maybe I’m biased, but we’ll want a piece of Brown in most formats.

Griffin Jax, SP/RP, Rays

The Rays love stuff, and Griffin Jax fits that mold. Jax went from a potential closer replacement for Pete Fairbanks in the offseason to some brutal appearances as a reliever. Since April 26, the Rays have moved Jax into the rotation by slowly ramping up his workload to five innings in his most recent start. Though Jax had a 1.29 ERA through four starts (14 innings), his 1.8% K-BB%, 1.21 WHIP, .250 BABIP, and 82.4% strand rate showed sketchy skills. Somehow, Jax’s elite swinging-strike rate (above 18% in 2024 and 2025) fell to 11.9% in 2026.

Over the past couple of starts, Jax consolidated his arsenal using the four-seam, sweeper, and sinker 65% of the time during his May 7 against the Red Sox and 77% of on May 13 versus the Blue Jays. That’s notable because Jax’s slider (17.2%) and changeup (20.2%) led his arsenal from a swinging-strike rate throughout his career. However, we’ve seen Jax’s slider (15.2%) and changeup (15.6%) take a step back in 2026.

Interestingly, Jax’s sweeper/slider lost three inches of downward movement and over two inches of glove-side sweep in 2026, as seen in the visual above. However, his sweeper’s pitch shape looks similar to 2024 from a vertical movement standpoint. That aligns with Jax’s sweeper/slider Stuff+ dropping to 112 in 2026, down from 127 (2025) and 116 (2024). Unfortunately, Jax’s sweeper/slider command dipped to a career-low (94), contributing to the overall decline in the Stuff+ grades.

Thankfully, Jax’s sweeper has been effective against right-handed hitters, allowing a .047 wOBA (.114 xwOBA) and eliciting a 21.4% swinging-strike rate. As a starter, we’ve seen Jax increase his sinker usage, though it fluctuated throughout 2026. He cut his sweeper usage by 10 percentage points in 2026 (39.3%) to right-handed hitters while throwing more sinkers (34.3%), a jump of nearly 12 points.

Jax’s sinker and changeup have similar induced movement profiles (both with 16.2 inches of arm-side run), something that might make it hard for hitters to identify. The sinker generates plenty of groundballs (78.6%), though right-handed hitters hit them relatively hard (.378 wOBA, .413 xwOBA). We’re highlighting the sinker because it appears he throws it a bit more toward the heart of the plate in 2026 than in 2025 against right-handed hitters, as seen in the heatmaps below.

That aligns with Jax’s sinker Location+ going from 115 (2025) to 99 (2026). Meanwhile, Jax throws a respectable amount of changeups (7.3%) toward right-handed hitters for whiffs (23.1% swinging-strike rate) and weak contact (.300 wOBA, .187 xwOBA), though it’s a tiny sample of 13 changeups in 2026. One could imagine that right-handed hitters might see the changeup and think it’s the sinker, only for it to drop 10 inches lower than the sinker.

I would love to see more changeups from Jax, especially against right-handed hitters, though there will probably be a bump against lefties. Based on the changeup heatmaps, we could anticipate opposing hitters chasing and whiffing at them when thrown low and below the zone.

Speaking of Jax’s pitch mix, specifically against lefties, let’s highlight a small part of Jax’s arsenal: his curveball. The curveball has been performing well against left-handed hitters. That’s evident by Jax’s curveball allowing a .150 wOBA (.173 xwOBA) against left-handed hitters in 2026, which can be seen in the rolling xwOBA visual below.

He has been throwing his curveball in the zone 30.4% of the time, generating whiffs (17.4% swinging-strike rate) and chases (37.5%) in 2026. For context, Jax’s curveball has a 7.2% swinging-strike rate and a 21.2% chase rate over his career. The improved results on the curveball gives him depth in his arsenal from a vertical movement standpoint after mostly having his pitches move horizontally.

We’ve seen the Rays develop former relievers into reliable starting pitchers. Last season, the Rays averaged 5.3 innings per game started and 83 pitches per start. Unfortunately, that’s fallen this year to  5 innings and 78 pitches per start. Jax averaging 5 innings per start and around 80 pitches will likely be the most realistic workload expectation.

He likely won’t log many quality starts or reach more than six innings often. However, Jax has a deep arsenal (3-4 pitches thrown over 10% of the time to either side of the plate), above-average stuff (106 Stuff+), and decent command (100 Location+). Without knowing a pitcher’s workload and team context, we typically want to invest in this profile. There’s a path for Jax to become a reliable starting pitcher, but fantasy managers will need to be patient – and realistic about the lack of wins/quality starts.

Walbert Urena, SP/RP, Angels

In Spring Training, I noticed someone named Walbert Urena was pumping gas, but I wasn’t sure about his fantasy relevance. Urena started the season out of the bullpen, before the Angels shifted him into the starting rotation. One of the best qualities in Urena’s profile is his heavy 52.1% groundball rate in 2026, similar to his minor league track record. That mainly comes via his changeup (58.8% groundball rate) and sinker (61.3%).

On the other side, walks have been and may continue to be an issue, evidenced by a high ball rate (41.2%) in 2026. That’s slightly higher than his 39.1% ball rate across two minor league levels (Double- and Triple-A) in 2025. Urena doesn’t generate many whiffs, with a mediocre 11.1% swinging-strike rate. However, pitchers can find success with an average swinging-strike rate while generating groundballs and limiting hard contact. Maybe the Angels like these types of pitchers; Jack Kochanowicz and José Soriano have similar groundball profiles.

Currently, Urena throws three pitches over 19% of the time to left-handed hitters. He throws plenty of changeups to lefties (45.8%) while mixing in two fastballs, including a sinker (26.9%) and four-seamer (19.2%). Urena’s changeup allows weak contact (.223 wOBA, .205 xwOBA) while generating a high amount of arm-side run (over 17 inches). Based on Urena’s changeup velocity and movement profile, it compares closely to other high-velocity changeups with above-average horizontal fade like the ones thrown by Dustin May, Paul Skenes, and Bubba Chandler.

Interestingly, Urena’s changeup and sinker locations tend to be quite similar, potentially making it challenging for opposing hitters. Though there’s a near seven mph difference in the sinker and changeup velocity, both pitches fade about 16-17 inches with five more inches of downward movement for the changeup. There’s a slight difference in Urena’s sinker and changeup locations against right-handed hitters, with them being located more toward the lower, inside corner of the zone.

Urena’s sinker has been crushed by righties, allowing a .528 wOBA (.439 xwOBA) in 2026. Though the sinker generated groundballs with a -4 degree launch angle, right-handed hitters are hitting them hard. However, the changeup (thrown 23.2% of the time toward right-handed hitters) elicits whiffs (30.3% swinging-strike rate) and weak contact (.169 wOBA, .109 xwOBA). We discussed how Urena’s changeup allows weak contact to lefties, but it’s worth noting the lower swinging-strike rate (13.1%). It’s unusual to find right-handed pitchers elicit more whiffs via changeups against right-handed hitters than lefties.

The visual below shows changeup whiffs against either side of the plate from Urena.

Most of Urena’s arsenal goes lower in the zone, except for his four-seamer. Urena’s four-seam averages 2.65 feet above the plate, nearly one foot higher than his sinker (1.85 feet). Like Urena’s other pitches, the four-seamer possesses plenty of arm-side run, over nine inches, leading to weak contact (.251 wOBA, .223 xwOBA) in the air (52.6% flyball rate). Urena seems to command his fastballs (four-seam and sinker) and changeups well. That’s true for the four-seamers (106 Location+) and changeups (131 Location+), though the stuff models don’t agree on the sinker with an 85 Location+.

Based on his arsenal moving mostly toward his arm side, it appears that Urena might be a pronator, with his sweeper being the only glove-side pitch. The sweeper is interesting from a stuff (114 Stuff+) and movement standpoint, but right-handed hitters are hitting them hard (.430 xwOBA) despite poor results (.278 wOBA), even when he locates them low and away from righties. Maybe Urena should add a gyro-like slider or cutter so his arsenal isn’t so predictable with the drastic glove- or arm-side movement profiles.

I wasn’t expecting to find this many interesting pieces of Urena’s arsenal. Since Urena’s pitches tend to have more horizontal movement, he can be successful by allowing weak contact, generating groundballs, and likely outpitching some ERA estimators because of his average strikeout skills.

Overall, Urena looks like a deep-league streaming pitcher with upside to develop into something similar to Soriano. Given the walks and groundballs, Urena could hurt your WHIP, so, understandably, fantasy managers might not feel warm and fuzzy in shallower formats.