Matt Waldron's brief Blue Jays run is already behind him, and Toronto's manager has watched another pitching-depth gamble take a sharp turn.

Toronto claimed Waldron off waivers from the San Diego Padres in early August, adding a veteran right-hander with one of baseball's most unusual arsenals.

The knuckleball made Waldron an intriguing depth option for a club that had spent much of the season searching for dependable innings beyond its established pitching staff.

But his stay with the Blue Jays unraveled quickly. Waldron posted a 10.38 ERA across 4.1 innings while appearing four times for Toronto.

He also struck out three batters before the Blue Jays designated him for assignment, ending his stint almost as quickly as it had started.

Washington then brought Waldron aboard, giving him another opportunity to stabilize his season and compete for innings with a new club.

The early returns were far better. Waldron delivered 5.2 scoreless innings after joining the Nationals and made one start before his latest setback.

Matt Waldron's fresh start hits an immediate setback

Washington placed Waldron on the 15-day injured list Tuesday with chest inflammation, with the move retroactive to Saturday.

The issue came after Waldron was struck in the chest by a comebacker while working on the mound, interrupting what had been a promising opening stretch with Washington.

His timing could hardly have been worse. Waldron had moved past his difficult Toronto showing and immediately given the Nationals useful innings before being removed from the active roster.

The injured-list move also delays his chance to build on that rebound. Based on the retroactive date, Waldron will be unavailable until at least Sept. 20.

For Toronto, the sequence underlines how difficult the search for usable pitching depth can become over a long season. Waldron offered a distinctive look, but the Blue Jays never received the stability they were seeking.

Patrick Corbin and Simeon Woods-Richardson have also been part of Toronto's effort to create more options, while Waldron's path became one of the more unusual chapters in that search.

Now Waldron's next test is simply getting healthy enough to return. His Nationals stint had started in encouraging fashion, only for an injury to stop that momentum almost immediately.