When looking at Royals pitching prospects with strong AFL campaigns this past week, right-hander A.J. Causey, a fifth-round pick by Kansas City in the 2024 MLB Draft, seems to stick out the most.
The University of Tennessee product pitched 3.2 innings for Surprise since Sunday, October 19th. In that sample, he posted a 2.45 ERA, 0.55 WHIP, and 35.7% K% and K-BB% (which was primarily due to him not walking a single batter). His full TJ Stats Summary from the AFL this past week can be seen below.
In addition to not walking a batter, Causey generated a substantial 63% strike percentage, a 50% zone rate, a 33.3% chase rate, and a 45.8% whiff rate. His primary pitch, the changeup, was his most impressive pitch in terms of generating chases and whiffs, as he produced 57.1% and 56.8% marks in those categories, respectively.
Interestingly enough, the 25-year-old righty produced strong results despite the stuff not being eye-popping. According to TJ Stuff+, he had an overall mark of 90, and his changeup, which he threw 50% of the time this past week, had a TJ Stuff+ of 83 and a grade of 32.
That stuff profile isn’t necessarily a recipe for success, but Causey has bucked that trend thanks to his strong command and unique arm angle. His nine-degree arm angle is pretty much a sidearm delivery, and it seems to have given hitters fits not just in the AFL this fall but also in the Midwest and Texas League last season.
Over 48 appearances and 73.1 IP with the River Bandits and Naturals last year, Causey posted a 1.72 ERA, a 2.28 FIP, a 0.90 WHIP, a 26.5% K rate, a 20.1% K-BB%, a 14.9% SwStr%, and a 30.4% CSW, according to Fangraphs.
When watching him in person or on tape, he also looks impressive. Causey has a strong propensity to fool batters and generate whiffs, as illustrated in this July 2nd outing for Quad Cities, where he struck out four batters.
Causey may be one of the biggest “dark horse” relievers for 2026, as I think he could make some noise in Spring Training this season. He’s not Rule 5 eligible until December of 2027, so the Royals have time with Causey and don’t need to add him to the 40-man roster right away. However, the fact that he’s already succeeded in Double-A (1.91 ERA and 2.39 FIP in 33 IP with the Naturals) is a good sign.
Additionally, he appears to have a strong head for the game and makeup, as illustrated in an interview with Drew Wheeler of Prospects Live.
Royals fans should continue to keep a close eye on Causey, especially this fall in Arizona, as we hit the second half of the AFL campaign.
Colleran: Another Sidearmer of Note
Dennis Colleran had only one outing this past week for the Saguaros, but it was a good one from a results and stuff standpoint. The 2024 7th round pick out of Northeastern allowed a home run, but that was the lone blemish as he struck out one and generated a 73.7% strike rate in his October 25th outing.
The TJ Stuff+ numbers stick out, even if the chase (16.7%), whiff (18.2%), and xwOBACON (.649) don’t. Colleran posted a 103 overall TJ Stuff+ with his slider and cutter, both sporting 108 marks. His stuff was looking much better than it did earlier in the AFL season.
That may be a sign that Colleran is getting more comfortable and settling into his comfort zone in Arizona. That should bode well for next spring, though he’s likely a Minor League camp pitcher. Like Causey, he’s got a bit of a sidearm delivery (17-degree arm angle), though not as extreme as his teammate’s.
Rough Stretch for Martin
If there’s a pitcher who wants to flush this past week from his memory, it is probably Logan Martin, who gave up six runs on five hits and two walks in his 1.2 inning outing on October 25th against Mesa. Much like Colleran, the stuff was there for Martin, but the results didn’t correlate, unfortunately.
Martin’s overall TJ Stuff+ was 101, and his primary two pitches, his four-seamer and cutter, posted TJ Stuff+ marks of 102 and 105. While he did generate a whiff rate of 30% on his four-seamer and 25% on his cutter, which are solid, he also gave up a lot of hard contact on the two pitches. He allowed a .671 xwOBACON on his four-seamer and .802 xwOBACON on his cutter. Add that with a zone rate of 37.8% overall, and it’s not surprising that Martin struggled so much.
Nonetheless, there’s a lot to like about Martin’s profile, especially his four-seamer, which has not only generated decent TJ Stuff+ marks this fall, but also features some quality iVB and spin.
Langevin: 2027 Royals Reliever “Dark Horse”?
The last Royals pitcher who saw some work this week was L.P. Langevin, who appeared in two outings and accumulated two innings of work. The good news? He didn’t allow a single run. The bad news? While his ERA was 0.00, his WHIP was 2.50, his FIP was 9.15, and his K-BB% was -36.4%.
Hence, control was a big problem for Langevin, who has primarily been a one-pitch reliever this fall in Surprise.
Langevin threw his sinker 85.5% of the time in his two outings this past week. Now, it’s a good pitch, as illustrated by a 102 TJ Stuff+, 28.6% chase, 25% whiff, and .048 xwOBACON this week. However, it posted a zone rate of only 40.4%, which explains the high walk rate and low strikeout rate.
The 22-year-old University of Louisiana-Lafayette product and Quebec City native is a raw talent who has dealt with some injury issues in his first full season of professional ball, limiting him to only 21.1 IP last year, mainly in High-A Quad Cities. However, Royals scouts have been super high on his stuff and potential, as highlighted in Anne Rogers’ piece after Langevin was drafted.
Here’s what Royals scouting director Brian Bridges said about Langevin and his fastball after they drafted him.
“You can’t really tell what it’s going to do,” scouting director Brian Bridges said of the heater. “Hitters will tell you, when he throws a ball that’s a hittable pitch, they swing at it like they didn’t see it or they swing right through it. He’s such a competitor and doesn’t think about those things, and he hasn’t been exposed to a lot of analytics and things that can help him. So we look forward to getting him out to Arizona. He’s a fun guy.”
Langevin is an easy guy to root for, as he showcased his personality in an interview with Jack Johnson of Locked On Royals last December.
Causey may be the best dark horse Royals reliever for 2026 right now in Arizona. However, Langevin may be a “late-blooming dark horse” for 2027, especially if he can iron out the command and repertoire a bit in the Minor Leagues this season.
Photo Credit: MLB.com/Royals