Reds’ Tony Santillan and Brandon Williamson progress in Louisville rehab outings

Cincinnati’s minor-league rehab timeline received a boost Sunday as Triple-A Louisville worked as a proving ground for two Reds relievers. Tony Santillan, rehabbing a left oblique strain, opened with a clean inning, retiring all three batters he faced and recording a strikeout. Brandon Williamson followed as the next high-leverage option on the day and delivered a longer, workload-oriented stint.

Santillan’s outing came in the kind of role teams use to evaluate both command and how a pitcher’s mechanics respond during live ball at-bats. According to MLB’s account of the game, he faced three batters and produced a perfect frame, with no runners reaching and one strikeout in the process. For a pitcher working around an oblique issue, the absence of traffic matters as much as the result, because it keeps the focus on repeatable delivery rather than quick re-set situations.

Williamson’s time on the mound was more expansive and designed to test stamina and rhythm. MLB reported that he threw 63 pitches, with 47 of them recorded for strikes, in 3 2/3 innings. Over that stretch, he allowed one run on five hits while striking out two and issuing no walks, a combination that suggests his control held even as the outing stretched beyond the opening frame.

The contrast between the two looks also helps clarify how teams structure rehab assignments. Santillan’s work was short and surgically targeted, functioning as an early checkpoint for how his arm and torso move when he has to finish a clean inning. Williamson’s outing, with a higher total pitch count and nearly four innings of work, looked more like a “next step” test for durability and for whether he can keep hitters off balance beyond a brief sample size.

For the Reds, the practical value of these outings is tied to bullpen depth. Relievers who can return without setbacks expand a manager’s late-game options and reduce the strain on other arms, especially as the organization navigates the final weeks of the season. Even though a rehab game is not the same as a major-league high-pressure appearance, it is a tangible reference point for when a pitcher might be ready to take on a more defined role again.

There is also an important caveat for fans: rehab success does not guarantee a specific return date. Teams typically monitor how each pitcher handles the next stages after a Triple-A outing, including additional throwing and how soreness responds after the game. Still, MLB’s description of Sunday’s outings points to both relievers completing their planned assignments without the kind of rough inning that forces a reevaluation of health or workload.

What to watch next is whether Louisville continues to provide progressive benchmarks for each pitcher. The next rehab steps usually look like building additional innings and pitch volume for longer-stint candidates, while shorter reliever re-checks often focus on consecutive outings and consistency. If both Santillan and Williamson keep moving forward through these checkpoints, Cincinnati will have clearer options for reshaping its bullpen rotation at the major-league level.

In the meantime, the immediate takeaway from Sunday is straightforward: Santillan delivered a perfect opener from the No. 1 “trial inning” role, and Williamson completed an extended, strike-leaning effort that produced one run with no free passes. Together, those performances offer the Reds a pair of tangible signs that their rehab plans are still progressing as intended.