MLB Pipeline Pitching Lab: How is Cardinals prospect Tekoah Roby rebuilding after Tommy John?

In the Arizona Fall League, the right-hander’s velocity and movement have returned in distinct, measurable ways as he fine-tunes a five-pitch mix that includes a high-spin four-seamer and a reshaped slider, sinker, and changeup.

By The Apex Times Newsroom2 min readAI-assisted Apex article

Tekoah Roby’s return from last year’s Tommy John surgery is being measured in the Arizona Fall League, where the Cardinals prospect debuted for Peoria on Oct. 9 and averaged 97.0 mph on 15 four-seam fastballs during his first AFL outing.

The velocity story has come with a broader “how” behind it. In the Fall League, Roby’s four-seam averaged 2,630 rpm and has played with enough ride to miss bats (AFL batters combined for two singles and eight strikeouts on the pitch through his early starts) while still showing limited arm-side movement.

Roby’s heat is only part of the explanation. MLB Pipeline’s Pitching Lab breakdown describes a pitch-shape plan built around locations that make his breaking pitches play better: he’s using the four-seamer as a setup, trying to get it to specific areas (including gloveside to right-handers and inside to left-handers) so the slider can perform off it.

Other secondary pitches remain in development, but with clear, trackable intent. Roby’s sinker is a work in progress, described as a one-seam grip that he’s been adjusting for more consistent “vertical kill” and execution to his arm-side; its average velocity in the AFL has been about 93.8 mph with additional drop and armside run compared to his four-seamer.

His curveball and slider are the most “defined” shapes in this phase. The curveball, a low-80s yakker, has averaged 2,800 rpm in the AFL and has produced both whiffs (58 percent) and chases (46 percent) in early use, while his gyro-style slider sits around 86-89 mph and has emphasized depth rather than sweep.

Roby has also leaned into a kick-change driven changeup action that he says helps him kill vertical break. In the AFL it’s been in the 83-85 mph range, and the stated goal moving forward is to locate it more consistently so it becomes more than a fourth or fifth option as his health and workload remain regular.

Why It Matters

For the Cardinals’ pitching pipeline, Roby’s measurable velocity return and pitch-spin profile give a clearer indicator than “feel” that his post-surgery work is translating to game action.
The AFL serving as a mid-autumn measuring stick means this rebuilding process is happening in front of evaluators, with his four-seam spin, slider shape, and curveball whiff rates functioning as concrete checkpoints.
If Roby’s secondary pitches keep stabilizing, the organization’s near-term roster-building plans could benefit from a starter track that has multiple distinct offerings rather than a one-pitch profile.
The stated trajectory is health first, then refinement toward a potential major league debut in 2027, making consistent location on his changeup and sinker especially important.

Sources

Key Facts

Tekoah Roby made his Arizona Fall League debut on Oct. 9 for Peoria after Tommy John surgery last year.
In that Oct. 9 outing, Roby averaged 97.0 mph on 15 four-seam fastballs.
In the AFL, Roby’s four-seam has averaged 2,630 rpm and has limited opponents to two singles and eight strikeouts on the pitch through his early starts.
MLB Pipeline reports Roby touched 97.5 mph or above in all three of his AFL outings to date while also seeing his four-seam velocity settle slightly.
Roby’s sinker is still being refined for consistency and “vertical kill,” while his curveball and gyro-style slider have shown distinct shapes and strong early bat-miss rates.
Roby’s changeup is based on a kick-change motion and sits about 83-85 mph in the Fall League, with consistent command identified as the next priority.