Spencer Schwellenbach is throwing bullpens and aiming for a September return, per report

Spencer Schwellenbach is reportedly throwing bullpen sessions and targeting a return sometime in September, according to a report from Yahoo Sports. For teams managing late-season roster construction, that kind of timetable matters because it can shape bullpen usage, starting rotation planning, and how aggressively a club might look for reinforcements at the next deadline checkpoint.

The report frames Schwellenbach’s progression as the next step in a broader recovery process, with bullpen work typically used to test mechanics and stamina against higher intensity pitching before any game action. While a September return is still a window, not a date, it provides a concrete reference point for a club that would rather plan than guess.

From a baseball operations standpoint, a pitcher working his way toward September can influence day-to-day decisions even before he is cleared for live games. If the staff believes a right-hander could be available after the calendar turns, it can affect how long relievers are asked to go between rest days and whether a starter is kept on a steadier pitch-count approach in earlier weeks.

The Yahoo Sports report also situates the update in the broader trade-deadline conversation, emphasizing that teams and fans are watching the “stove” as Monday, August 3 at 6 pm ET approaches. In many seasons, that deadline window is where clubs either address immediate needs or decide to stand pat. A credible internal recovery path, such as a mid-to-late-season pitching target, can reduce the pressure to chase a veteran arm purely for depth.

Still, bullpen-to-starting-pitcher progression is rarely linear. Even when a pitcher is throwing bullpens, there are variables that can shift timelines, including how his command holds at higher effort, how hitters look off pitch sequences, and how the body responds after consecutive days of work. The report’s September aim should be viewed as conditional on continued progress, not as a guarantee of availability.

For Schwellenbach personally, the next phase is typically about building live-game readiness. That usually involves extending intensity, adding situational elements that resemble real at-bats, and then transitioning to higher-leverage work under game conditions. If everything stays on track, the payoff for a club is having a starter-capable option or a rotation-flex piece during the final month when teams face travel-heavy series and must manage innings carefully.

What to watch next is whether the team confirms additional steps after bullpens, such as progression to simulated game work and, eventually, live batting practice or an assignment that indicates a move from rehab to activation planning. Until there is official confirmation, the best interpretation of the report is that Schwellenbach is moving in the right direction and that a September timeline is the current working target.

With MLB’s August 3 deadline window approaching, this type of update often has ripple effects across roster strategy. If September availability becomes more certain, it can influence how a club balances short-term bullpen needs against longer-term rotation flexibility. If it does not, it raises the odds that the club will need other solutions before playoff positioning tightens.