MLB Pipeline Pitching Lab: Tekoah Roby

PEORIA, Ariz. -- Tekoah Roby returned to the mound at full throttle, or so it seemed.

After last year’s Tommy John surgery, the Cardinals’ No. 14 prospect made his 2026 debut for Peoria in the Arizona Fall League on Oct. 9 and averaged 97.0 mph over 15 four-seam fastballs thrown in three no-hit innings at Surprise. That was a notable bump from his 95.3 mph average in six starts at Triple-A Memphis in 2025 before the elbow injury and enough of a boost to set off excitement in certain circles.

Hold your horses, says the right-hander, at least for now.

“I think that’s just the first time being truly in a game in a stadium against another team with fans in the stands and things like that,” Roby said. “That was mostly adrenaline. I don’t think I can expect that every time.”

While that velo settled back a bit in Roby’s two Fall League starts since, there are still plenty of encouraging signs for the 25-year-old, who has yet to allow a run through three starts (9 ⅔ innings) while striking out 13 and walking only one in that span.

To break down what’s been working for him post-TJ, Roby spoke to MLB Pipeline about the grips and effectiveness of his five offerings in the latest edition of the Pitching Lab:

FOUR-SEAMER

It’s a pretty standard four-seam grip for Roby with the loop of the horseshoe to his right and his pointer and middle fingers close together right on top of the seam with the thumb tucked under. He averaged 95.6 mph with it in his second outing on Oct. 15 and 95.8 on Wednesday, so his note about adrenaline in that 2026 debut certainly rings true. But he’s touched 97.5 mph or above in all three of his outings to this point, so the high-end velocity is still notable. 

Even more so is the spin; Roby has averaged 2,630 rpm on his four-seamer so far in the Fall League. That’s in line with Jacob Misiorowski (2,635) and Chase Burns (2,633), who ranked third and fourth among MLB qualifiers in average four-seamer spin rate. There’s decent ride on it (around 15-16 inches on average) and limited horizontal movement to the armside (typically around 6 inches), but AFL batters haven’t been able to handle the spin plus the heat with only two singles and eight whiffs (on 30 swings for a 27 percent miss rate) against the four-seamer to this point.

Despite that success, Roby still sees the primary heater, which he’s only thrown 33 percent of the time in the AFL, as a setup option.

“What I'm looking for out of this pitch is just trying to throw it to different locations in the zone to then help my breaking stuff play a little bit better,” he said. “So I'm trying to get it to the gloveside to righties, so that the slider plays a little bit better off it and then go off of that. Then to the lefties, I really like to get it in, and then that opens up the outside.”

SINKER

While Roby's dialed in on what works with the four-seamer, he is still tinkering with the sinker to find something that consistently drops in the way he desires. His current version -- using some inspiration from Mason Englert, a former teammate in the Rangers system, and Sonny Gray -- remains a work in progress.

“I've been messing around with a few different things,” Roby said. “Really, it's kind of more of a one-seam grip. But I've kind of played with moving up a little bit, being further back, and then even something a little bit further this way [right on top of the two seams] to try and get just a little bit more consistent. The velo’s kind of a priority with it, but I'm really just trying to find ways to consistently kill vert and be able to execute to my armside.”

That velocity has been 93.8 mph on average in the Fall League, so a few ticks below the four-seamer, but to Roby’s point about vertical action, the sinker typically gets 9-10 inches of additional drop and 7 inches of added armside run. Between the AFL and Triple-A, Roby has reserved the sinker solely for righties with none thrown to opposite-side bats in either setting.

CURVEBALL

This is Roby’s bread-and-butter. 

“It’s one of those things that I've been doing for so long,” he said. “It's just really second nature at this point.”

With his first two fingers along the seam, Roby pushes his grip to the back of the horseshoe, emphasizes the pressure on his middle finger and uses a distinct trigger to rip the curveball through his motion.

“I’m trying to feel like honestly sometimes the back of my hand is toward the plate as I’m coming through,” he said, “and then it naturally pronates forward, and that gives it that top-down movement.”

The result is a low-80s yakker that drops more than 4 feet and has modest sweep with significant spin. Roby’s curveball has averaged 2,800 rpm in the Fall League, which would rank 38th among MLB qualifiers, and the late movement has befuddled both righties and lefties in the desert with a 58 percent whiff and 46 percent chase rate through three starts. With those results, the plus pitch has been used twice as often as any other secondary and almost as much as the four-seamer (31 times vs. 33) as Roby finds his footing again.

SLIDER

Roby changed which side of the ball he threw the slider from ahead of the 2025 season and saw cutter-like results out of the gate. He shifted to a more straightforward slider grip as he sought more depth and continued to play around with how deep in his hand he holds the baseball for the slider, which now sits around 86-89 mph. 

His ideal shape is that of the gyro slider with an average of 0-1 inch of horizontal movement (i.e., not a sweeper) because of the way he’s trying to fight off splits. Think of it as a quicker, shorter version of the deuce.

“Gyros historically play really well to both sides of the plate,” he said. “Sweepers are really going to play better to the same side of handedness. To be honest, I've never really been able to sweep the ball a ton that way. So this is the one that came out. … I want to be able to neutralize both sides, especially as I try to get deeper into games.”

Of the 23 sliders he’s thrown in the AFL, 16 have been to righties, five of which have resulted in whiffs, but there’s enough usage in there to give lefties something to consider.

CHANGEUP

“Another one that’s inconsistent right now,” Roby said when the changeup was mentioned.

He joined the kick-change revolution in 2025, spiking his middle finger to get some of the action he had sought out but wasn’t getting from previous versions of the cambio.

“It just helps me kill vert,” he said. “Historically, I’ve been really bad at killing vert on changeups. Then in 2025, I started doing this, the shape was great, and I’ve just stuck with it.”

The changeup now sits 83-85 mph with, at times, negative induced vertical break and a little less armside run than the sinker. Locating it consistently will be the goal moving forward to make it something better than a standard fourth or fifth option. But now that Roby is healthy and on the mound consistently in the Fall League, that work can continue in earnest ahead of a possible MLB debut with St. Louis in ‘27.