In my last post, I profiled the three Royals hitting prospects currently playing in the AFL with the Surprise Saguaros: Blake Mitchell, Daniel Vazquez, and Carson Roccaforte. The Saguaros have a double header today, and both Vazquez and Roccaforte had solid performances at the plate in a 6-3 win over the Glendale Desert Dogs in game one.
In this post, I am going to profile the five Royals pitching prospects currently pitching for the Saguaros. None of the five pitchers is as heralded as the three position prospects in Surprise. That said, they are intriguing arms who should be paid attention to, not just in the Arizona Fall League, but in Spring Training next year.
Hunter Owen, LHP (No. 26 Ranking)
Owen made the Surprise squad after a pretty solid full season with the Northwest Arkansas Naturals.
In 22 starts and 94.2 IP, the former Vanderbilt product posted a 3.80 ERA, 1.33 WHIP, and 4.02 FIP. Even though he threw 7.1 fewer innings in Double-A this year (Owen pitched primarily in High-A in 2024), he improved his K rate by seven percent, his K-BB% by 4.9%, and FIP by 14 points.
The 2023 4th round pick by the Royals was particularly stellar in August with the Naturals. In four games and 18.1 IP, he posted a 1.96 ERA and struck out 21 batters while only walking one. That performance helped him earn Northwest Arkansas August Pitcher of the Month honors.
What makes Owen so effective as a pitcher is that he attacks the zone and limits walks. He got hit a bit more in Double-A than High-A ball in 2024, as illustrated by his 9.4% HR/FB rate, which was 1.8% higher than his mark in Quad Cities. Nonetheless, when Owen was locating, he was tough to hit, as illustrated in a May 10th outing against Wichita, where he went six scoreless innings with seven strikeouts.
It hasn’t been the best start for Owen in Surprise so far in the AFL. In 4.1 IP, he has a 12.46 ERA and 2.77 WHIP. His FIP is better at 5.00, but that’s still not an impressive mark, especially for his standards.
Interestingly enough, Owen is just getting hit, as he’s allowed 11 hits so far in the AFL. The .440 xwOBACON indicates that AFL opposing hitters are knocking him around, and the 22.2% whiff rate further illustrates that he’s not blowing batters away (his 16.1% K rate also confirms this).
On a positive note, the lefty hasn’t given up a home run this fall, and he’s still flooding the zone, which was his calling card as a pitcher this past season. His zone rate is currently 51.6% and he’s demonstrated a high zone rate with his primary pitch: the four-seamer (66.7%). He’s also generating a 36.2% chase rate, which is a good sign. That means that hitters are swinging at a lot of lackluster quality pitches out of the zone, which could result in some BABIP regression in the future.
The TJ Stuff+ in the AFL for Owen has been okay, but not great.
He’s posting a 96 overall TJ Stuff+ and his changeup and curveball rate decently (98) while his slider rates as a plus pitch (104). His four-seamer and sinker, however, both sport 91 TJ Stuff+ marks, which is not great, especially since the four-seamer is his primary pitch with a 39.6% usage.
The lackluster Stuff marks on the four-seamer make me wonder if there may be some fatigue there. That is something to watch out for since an injury kept him from pitching in 2023 immediately after being drafted. That could result in his AFL campaign ending sooner rather than later.
Logan Martin, RHP (NR Overall Ranking; 17th-Ranked Pitcher)
Martin was a 12th-round pick out of Kentucky in 2023, and he has made incremental progress in the Royals system since making his debut shortly after being drafted.
After posting a 2.25 ERA in eight innings between the Complex League and Carolina League (Low-A), he threw 102 innings in 2024 with the Fireflies and posted a 3.62 ERA, 1.17 WHIP, and 3.57 FIP. He also posted a 22.9% strikeout rate and 15.3% K-BB%, both solid marks for a starting pitcher in his first full Minor League season. He ended up being one of the more effective starters in a Columbia rotation that also included names like Blake Wolters, Hiro Wyatt, Emmanuel Reyes, and Felix Arronde.
Martin made the transition to High-A ball in 2025 and posted a 3.45 ERA, 1.20 WHIP, and 3.79 FIP in 91.1 IP with the River Bandits. The K rate did decline by 2.3%, and his K-BB% regressed by 4.2%. However, he still proved to be one of the more dependable starters for the River Bandits (22 starts), and he also decreased his HR/FB rate by 1.6%.
Martin’s made two starts in the AFL and has produced mixed results. He had a strong initial outing with three scoreless innings, but got more lit up in his second outing. In 5.2 IP, his ERA is 4.76, but his WHIP is 1.59 and his FIP is 4.91. The former Kentucky product has also walked more batters (four) than he’s struck out (1).
The stuff has been fine, for the most part, according to TJ Stats. He sports an overall TJ Stuff+ mark of 101, and his two primary pitches, his four-seamer and cutter, have TJ Stuff+ marks of 100 and 103, respectively. However, he is struggling to find the strike zone this fall, with a 37.9% zone rate overall. Thus, that lack of control has caused hitters to be more selective, and they are not just chasing less (27.1%) but also whiffing less (18.2%).
The good thing about Martin this year, via TJ Stats, is that he is limiting hard contact. His xwOBACON is .215, which has helped him keep his ERA in check, despite the lackluster command and control. It will be interesting to see if Martin can stabilize that command a bit in future starts this fall, which hopefully will help him boost those K and K-BB numbers.
Dennis Colleran, RHP (Not Ranked)
A 7th-round pick in the 2024 MLB Draft out of Northeastern, Colleran pitched at three levels for the Royals in 2025 (Low-A, High-A, and Double-A). Over those three stops, the 22-year-old reliever posted a 2.85 ERA, 1.06 WHIP, 27.1% K rate, and 3.91 WHIP in 66.1 IP. While that’s not Trey Yesavage-esque progress, it still is encouraging to see, especially for a guy coming off injury in his final season at Northeastern.
Colleran is known for his power fastball, which surpassed the 100 MPH mark this past Minor League season. That ability will help him move quickly again in the Royals system in 2026.
With the Saguaros this fall, he hasn’t allowed an earned run in three innings of work, and he’s also posting a 1.00 WHIP and 3.48 FIP. His walk rate is high at 16.7%, but he’s making up for it with a 33.3% strikeout rate and 16.7% K-BB%.
Interestingly enough, Colleran isn’t generating a whole lot of whiffs or chases. His whiff rate is 14.3% and his chase is 13%. On a positive note, his xwOBACON is .199, which shows that hitters haven’t been able to square up his electric stuff.
Speaking of stuff, while his sinker and four-seamer are averaging 97 and 96.9 MPH, respectively, his cutter has been his best pitch on a TJ Stuff+ end. The cutter has a 101 mark, much better than his sinker (91) and four-seamer (93). Thus, it’s not surprising that his cutter has been his primary pitch thrown this fall in Arizona.
A.J. Causey, RHP (Not Ranked)
A tall, lanky 5th-round pick out of Tennessee, Causey succeeded as a reliever in High-A and Double-A in 2025. In 73.1 IP between the River Bandits and Naturals, he posted a 1.72 ERA, 0.90 WHIP, a 20.1% K-BB%, and 2.28 FIP. One could argue that Causey was the best reliever in the Royals’ farm system a season ago.
It’s been a rough AFL debut for Causey. In 2.2 IP, he’s allowed a 20.25 ERA, 2.63 WHIP, and 7.28 FIP. Those metrics have come on six runs allowed on six hits, with one of those being a home run.
A deeper dive into his swing-and-miss metrics should paint a more encouraging picture of Causey. His K rate is still strong at 26.7%, as is his 20% K-BB%. His whiff rate is also 40%, with his changeup generating a 58.3% whiff rate and his curveball generating a 66.7%. Those are elite rates and show what he’s capable of when he’s commanding effectively.
I guess that the hitter-friendly environment of Arizona has affected him, and he just isn’t locating as effectively as he would like. His zone rate is only 41.3% and his xwOBACON allowed is .451, both subpar marks. He needs to improve as he pitches more in the AFL.
However, his strong strikeout and whiff numbers make me hopeful that the high ERA and WHIP numbers are due to a bad stretch and aren’t cause for long-term concern.
L.P. Langevin, RHP (Not Ranked)
Langevin, a fourth-round pick in 2024 out of Louisiana, only pitched 21.1 innings between the Complex and High-A ball due to recovery from a lat strain. The ERA wasn’t great at 5.91, and he struggled with control, but he showed excellent strikeout stuff with a 29.8% K rate.
With so few innings the past season, it makes sense that Langevin is in the AFL to get more work. He’s generating plenty of whiffs with Surprise, as he is posting a 33.3% strikeout rate and 46.2% whiff rate. Unfortunately, his zone rate is slightly subpar at 46.3%, his chase rate is low at 13.6%, and his walk rate is high at 33.3%.
To make matters worse, it seems like he was dealing with some injury issues in his last outing, as he was pulled before even making a pitch.
Langevin is a project in every sense of the word. The stuff is there. His TJ Stuff+ is 101 overall, and his sinker has a 62 grade, producing a 50% whiff rate and 0.080 xWOBACON. That’s elite for a pitch he has thrown 85.4% of the time this fall in Arizona.
In an October 9th outing against the Desert Dogs, he demonstrated what he can do when the command and stuff click.
There is MLB-level closer potential with Langevin. Unfortunately, he also has the kind of command and injury history that could put him out of baseball in a few years.
Let’s hope it’s the former, not the latter, as Langevin is a fun pitcher to watch.
Photo Credit: Chris Shepard