Williams was left off the Brewers' wild-card roster Wednesday due to right shoulder soreness, Jeff Passan of ESPN.com reports.
The news of Williams' injury comes out of nowhere, as the 26-year-old wasn't known to be dealing with any issues coming out of his final appearance of the regular season Friday. His absence for the three-game series is a major blow for the Brewers, as Williams was arguably the best reliever in baseball this season. In 27 innings out of the bullpen, he struck out 53 batters (good for a 53.0 percent strikeout rate, as he faced exactly 100 batters) while allowing just a single earned run.